Methods for treating an impairment in memory consolidation

ABSTRACT

Impairments in memory consolidation are treated with an amphetamine compound. In one embodiment, the method includes administering an l-amphetamine compound. In another embodiment, the method includes administering an l-methamphetamine compound. The method can include determining memory consolidation before, during and/or after administering the amphetamine compound.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/444,970, filed May 23, 2003, which is a continuation-in-part of U.S.application Ser. No. 10/139,606, filed May 2, 2002, which is acontinuation-in-part of U.S. application Ser. No. 10/003,740 filed Oct.31, 2001, which claims the benefit of U.S. Provisional Application No.60/245,323 filed on Nov. 1, 2000 and claims priority to InternationalApplication PCT/US01/45793, filed Oct. 31, 2001, which designates theUnited States and was published in English. The teachings of the aboveapplications are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

The term “memory” subsumes many different processes and requires thefunction of many different brain areas. Overall, human memory providesdeclarative recall, e.g., for facts and events accessible to consciousrecollection, and non-declarative recall, e.g., procedural memory ofskills and operations not stored regarding time and place. Research inrecent years has provided information necessary to understand many ofthe various components of memory and has identified associated brainregions. A newly acquired experience initially is susceptible to variousforms of disruption. With time, however, the new experience becomesresistant to disruption. This observation has been interpreted toindicate that a labile, working, short-term memory is consolidated intoa more stable, long-term memory.

Behavioral research has found that the human mind consolidates memory atcertain key time intervals. The initial phase of memory consolidationoccurs in the first few minutes after an exposure to a new idea orlearning experience. The next phase occurs over a longer period of time,such as during sleep. If a learning experience has on-going meaning tous, the next week or so serves as a further period of memoryconsolidation. In effect, in this phase, the memory moves fromshort-term to long-term storage.

Moreover, various mechanisms have been proposed to account for theformation of long-term memory. A wide range of observations suggest anevolutionarily conserved molecular mechanism involved with the formationof long-term memory. These include increased release of synaptictransmitter, increased number of synaptic receptors, decreased K_(D) ofreceptors, synthesis of new memory factors either in the presynaptic orpostsynaptic element, sprouting of new synaptic connections, increase ofthe active area in the presynaptic membrane and many others. Synapticplasticity, the change in the strength of neuronal connections in thebrain, is thought to underlie long-term memory storage.

Memory consolidation, the process of storing new information inlong-term memory is also believed to play a crucial role in a variety ofneurological and mental disorders, including mental retardation,Alzheimer's disease and depression. Indeed, loss or impairment oflong-term memory is a significant feature of such diseases, and noeffective therapy for that effect has emerged. Short-term, or “working”memory, is generally not significantly impaired in such patients.

Accordingly, methods and compositions that enhance long-term memoryfunction and/or performance, or prophylactically (e.g., as aneuroprotective treatment) prevent or slow degradation of long-termmemory function and/or performance would be desirable. Similarly,methods and compositions for restoring long-term memory function and/orperformance are needed.

Impairments in memory consolidation in a human can occur in a number ofconditions or diseases, such as age-related memory loss, Alzheimer'sdisease, Multiple Sclerosis, brain injury, brain aneurysm, stroke,schizophrenia and epilepsy. Clinical management strategies currentlyprovide minimal, if any, improvement in memory. Thus, there is a need todevelop new, improved and effective methods for the treatment of a humansuffering with an impairment in the formation of memory consolidation.

SUMMARY OF THE INVENTION

The present invention relates to methods of treating a human having animpairment in memory. The human can have an impairment in memoryconsolidation (the process of storing new information in long termmemory) or an impairment in short term memory processes. The humans aretreated with the amphetamine class of compounds (collectively referredto herein as “amphetamine compounds”) to enhance, prevent and/or restorelong-term memory function and performance, e.g., to improve the processof storing new information in long term memory in humans (memoryconsolidation) or to improve short term memory. More particularly, theinvention relates to the discovery that a particular enantiomer ofamphetamine compounds (R)-(−)-amphetamine (l-amphetamine,levo-amphetamine) or (R)-(−)-methamphetamine (l-methamphetamine,levo-methamphetamine) is effective for treating humans having animpairment in memory consolidation.

In one embodiment, the invention includes a method of improving memoryconsolidation in a human, comprising the step of administering at leastone member selected from the group consisting of l-amphetamine andl-methamphetamine to a human having an impairment in memoryconsolidation.

In another embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering atleast one member selected from the group consisting of l-amphetamine andl-methamphetamine to a human having an impairment in memoryconsolidation, wherein the l-amphetamine is at least about 80 molepercent l-amphetamine relative to d-amphetamine and thel-methamphetamine is at least about 80 mole percent l-methamphetaminerelative to d-methamphetamine.

In yet another embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering atleast one member selected from the group consisting of l-amphetamine andl-methamphetamine to a human having an impairment in memoryconsolidation, wherein the l-amphetamine is at least about 90 molepercent l-amphetamine relative to d-amphetamine and thel-methamphetamine is at least about 90 mole percent l-methamphetaminerelative to d-methamphetamine.

An additional embodiment of the invention includes a method of improvingmemory consolidation in a human, comprising the steps of assessing thedegree of an impairment in memory consolidation in a human;administering at least one member selected from the group consisting ofl-amphetamine and l-methamphetamine to the human; and determining theimprovement in memory consolidation after administering thel-amphetamine and l-methamphetamine to the human.

In still another embodiment, the invention includes a method ofimproving memory consolidation in a human, comprising the step ofadministering an amphetamine to a human having an impairment in memoryconsolidation in an amount effective to improve memory consolidation inthe human, wherein the amphetamine is at least about 85 mole percentl-amphetamine.

In another embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is at least about 80 mole percent l-amphetamine.

Another embodiment of the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is at least about 99 mole percent l-amphetamineand the l-amphetamine is administered to the human in a dose of at leastabout a 0.01 mg dose.

In yet another embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is at least about 90 mole percent l-amphetamineand the l-amphetamine is administered to the human in a dose betweenabout a 0.01 mg dose to about a 125 mg dose.

In an additional embodiment, the invention includes a method ofimproving memory consolidation in a human, comprising the step ofadministering an amphetamine to a human having an impairment in memoryconsolidation in an amount effective to improve memory consolidation inthe human, wherein the amphetamine is at least about 80 mole percentl-amphetamine and the l-amphetamine is administered to the human in adose at lease about a 0.01 mg dose.

In a further embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is between about 80 mole percent l-amphetamineto about 99 mole percent l-amphetamine.

In still another embodiment, the invention includes a method ofimproving memory consolidation in a human, comprising the step ofadministering an amphetamine to a human having an impairment in memoryconsolidation in an amount effective to improve memory consolidation inthe human, wherein the amphetamine is between about 80 mole percentl-amphetamine to about 99 mole percent l-amphetamine and thel-amphetamine is administered to the human in a dose at least about a0.01 mg dose.

Another embodiment of the invention includes a method of improvingmemory consolidation in a human comprising assessing the degree ofimpairment in memory consolidation in a human having an impairment inmemory consolidation and administering an amphetamine to the human in anamount effective to improve memory consolidation in the human, whereinthe amphetamine is at least about 80 mole percent l-amphetamine. Theimprovement in memory consolidation after administering the amphetamineto the human is determined.

In an additional embodiment, the invention includes a method ofimproving memory consolidation in a human, comprising the step ofadministering an amphetamine to a human having an impairment in memoryconsolidation in an amount effective to improve memory consolidation inthe human, wherein the amphetamine is at least about 90 mole percentl-amphetamine and has the structural formula:

In still another embodiment, the invention includes a method ofimproving memory consolidation in a human, comprising the step ofadministering an amphetamine to a human having an impairment in memoryconsolidation in an amount effective to improve memory consolidation inthe human, wherein the amphetamine is at least about 90 mole percentl-methamphetamine.

In a further embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is at least about 85 mole percentl-methamphetamine.

An additional embodiment of the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is at least about 80 mole percentl-methamphetamine.

In yet another embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is at least about 99 mole percentl-methamphetamine and the dose of l-methamphetamine administered to thehuman is at least about a 0.01 mg dose.

Another embodiment of the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is at least about 90 mole percentl-methamphetamine and the l-methamphetamine is administered to the humanin a dose at least about a 0.01 mg dose.

In yet another embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is at least about 80 mole percentl-methamphetamine and the dose of l-methamphetamine administered to thehuman is at least about a 0.01 mg dose.

In a further embodiment, the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is between about 80 mole percentl-methamphetamine to about 99 mole percent l-methamphetamine.

An additional embodiment of the invention includes a method of improvingmemory consolidation in a human, comprising the step of administering anamphetamine to a human having an impairment in memory consolidation inan amount effective to improve memory consolidation in the human,wherein the amphetamine is between about 80 mole percentl-methamphetamine to about 99 mole percent l-methamphetamine and thel-methamphetamine is administered to the human in a dose at least abouta 0.01 mg dose.

Another embodiment of the invention includes a method of improvingmemory consolidation in a human, comprising assessing the degree ofimpairment in memory consolidation in a human having an impairment inmemory consolidation and administering an amphetamine to the human in anamount effective to improve memory consolidation in the human, whereinthe amphetamine is at least about 80 mole percent l-methamphetamine. Theimprovement in memory consolidation after administering the amphetamineto the human is determined.

In an additional embodiment, the invention includes a method ofimproving memory consolidation in a human, comprising the step ofadministering an amphetamine to a human having an impairment in memoryconsolidation in an amount effective to improve memory consolidation inthe human, wherein the amphetamine is at least about 90 mole percentl-methamphetamine and has the structural formula:

In one embodiment, the invention is a pharmaceutical kit comprising oneor more amphetamine compound(s) in an amount sufficient to enhancelong-term memory in a patient, a pharmaceutically acceptable carrier,and instructions (written and/or pictorial) describing the use of theformulation for enhancing memory.

In another embodiment, the invention is a pharmaceutical preparationcomprising one or more amphetamine compounds provided as a single oraldosage formulation in an amount sufficient to enhance long-term memoryin a patient but resulting in a concentration in the patient lower thanits EC₅₀ as a CNS stimulant.

In still another embodiment, the invention is a pharmaceuticalpreparation comprising one or more amphetamine compounds provided in theform of a transdermal patch and formulated for sustained release of theamphetamine(s) in order to administer an amount sufficient to enhancelong-term memory in a patient but resulting in a concentration in thepatient lower than its EC₅₀ as a CNS stimulant.

In particular embodiments, the pharmaceutical kits and preparations ofthe invention comprise at least one of the amphetamine compoundsrepresented by Formula I, or a pharmaceutically acceptable salt,solvate, metabolite or pro-drug thereof:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl;    -   R₂ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₃ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, selected from the group consisting of hydrogen,        halogen, hydroxy, alkoxy, amino, alkylamino, sulfhydryl,        alkylthio, cyano, nitro, ester, ketone, formyl, amido,        acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonate ester,        amidino, sulfonyl, sulfoxido, sulfamoyl, and sulfonamido.

In certain embodiments, R₃ represents hydrogen, while in otherembodiments, R₃ represents lower alkyl, such as methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl, t-butyl, etc., hydroxy, amino, orcarbonyl.

In certain embodiments, R₄ represents hydrogen, while in otherembodiments, R₄ represents from 1 to 3 substituents on the ring to whichit is attached selected from halogen, hydroxy, amino, sulfhydryl, cyano,nitro, lower alkyl, and sulfate.

In certain embodiments, R₄ represents hydrogen and at least one of R₁,R₂, and R₃ represents hydrogen. In certain embodiments, R₄ representshydrogen and at least two of R₁, R₂, and R₃ represents hydrogen. Incertain embodiments, R₄ represents hydrogen and at least three of R₁,R₂, and R₃ represent hydrogen. In certain embodiments, R₄ representshydrogen and all four of R₁, R₂, and R₃ represent hydrogen.

In certain embodiments, one R₁ represents hydrogen, one R₁ representslower alkyl, such as methyl, ethyl, propyl, isopropyl, n-butyl,isobutyl, t-butyl, etc., R₂ represents lower alkyl, such as methyl,ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, etc., R₃ and R₄represent hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 3 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In most preferred embodiments, R₁, independently and for eachoccurrence, represents hydrogen, R₂ represents methyl, and R₃ and R₄independently and for each occurrence represent hydrogen.

In other preferred embodiments the pharmaceutical kits and preparationsof this invention comprise at least one of the amphetamine compounds asa pharmaceutically acceptable salt represented by Formula II:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl;    -   R₂ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₃ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, selected from the group consisting of hydrogen,        halogen, hydroxy, alkoxy, amino, alkylamino, sulfhydryl,        alkylthio, cyano, nitro, ester, ketone, formyl, amido,        acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonate ester,        amidino, sulfonyl, sulfoxido, sulfamoyl, and sulfonamido; and    -   L is a non-toxic organic or inorganic acid.

In certain embodiments, R₃ represents hydrogen, while in otherembodiments, R₃ represents lower alkyl, such as methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl, t-butyl, etc., hydroxy, amino, orcarbonyl.

In certain embodiments, R₄ represents hydrogen, while in otherembodiments, R₄ represents from 1 to 3 substituents on the ring to whichit is attached selected from halogen, hydroxy, amino, sulfhydryl, cyano,nitro, lower alkyl, and sulfate.

In certain embodiments, R₄ represents hydrogen and at least one of R₁,R₂, and R₃ represents hydrogen. In certain embodiments, R₄ representshydrogen and at least two of R₁, R₂, and R₃ represents hydrogen. Incertain embodiments, R₄ represents hydrogen and at least three of R₁,R₂, and R₃ represent hydrogen. In certain embodiments, R₄ representshydrogen and all four of R₁, R₂, and R₃ represent hydrogen.

In certain embodiments, one R₁ represents hydrogen, one R₁ representlower alkyl, such as methyl, ethyl, propyl, isopropyl, n-butyl,isobutyl, t-butyl, etc., R₂ represents lower alkyl, such as methyl,ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, etc., R₃ and R₄represent hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 2 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In most preferred embodiments, R₁, independently and for eachoccurrence, represents hydrogen, R₂ represents methyl, and R₃ and R₄independently and for each occurrence represent hydrogen.

In other preferred embodiments the pharmaceutical kits and preparationsof this invention comprise at least one of the amphetamine compounds asan amphetamine metabolite represented by Formula III:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₂ represents hydrogen or lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₃ represents hydrogen or lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, e.g., selected from hydrogen, halogen, hydroxy,        alkoxy, amino, alkylamino, sulfhydryl, alkylthio, cyano, nitro,        ester, ketone, formyl, amido, acylamino, acyloxy, lower alkyl,        lower alkenyl, sulfonate ester, amidino, sulfonyl, sulfoxido,        sulfamoyl, and sulfonamido;    -   R₅ independently for each occurrence, represents hydrogen or        hydroxy.

In certain embodiments, R₃ represents hydrogen, while in otherembodiments, R₃ represents lower alkyl, such as methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl, t-butyl, etc., hydroxy, amino, orcarbonyl.

In certain embodiments, R₄ represents hydrogen, while in otherembodiments, R₄ represents from 1 to 3 substituents on the ring to whichit is attached selected from halogen, hydroxy, amino, sulfhydryl, cyano,nitro, lower alkyl, and sulfate.

In certain embodiments, R₄ represents hydrogen and at least one of R₁,R₂, and R₃ represents hydrogen. In certain embodiments, R₄ representshydrogen and at least two of R₁, R₂, and R₃ represent hydrogen. Incertain embodiments, R₄ represents hydrogen and at least three of R₁,R₂, and R₃ represent hydrogen. In certain embodiments, R₄ representshydrogen and all four of R₁, R₂, and R₃ represent hydrogen.

In certain embodiments, one R₁ represents hydrogen, one R₁ representlower alkyl, such as methyl, ethyl, propyl, isopropyl, n-butyl,isobutyl, t-butyl, etc., R₂ represents lower alkyl, such as methyl,ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, etc., R₃ and R₄represent hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 2 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In one embodiment, R₁, independently and for each occurrence, representshydrogen, R₂ represents methyl, and R₃ and R₄ independently and for eachoccurrence represent hydrogen.

In another embodiment, a metabolite of an amphetamine compound isselected from p-hydroxyamphetamine, benzyl methyl ketone,1-phenylpropan-2-ol, benzoic acid, glycine, hippuric acid,p-hydroxynorephedrine, and N-hydroxylamphetamine.

In particular embodiments of the kits, preparations, compositions andmethods, the invention features a pharmaceutical kit or preparationcomprising a mixture of at least a single species of amphetaminecompounds or at least two different species of amphetamine compounds.The different species of amphetamine compounds can be present in equalor in differing amounts with respect to one another.

In another embodiment of the kits, preparations, compositions andmethods, the invention features a composition comprising at least about51 percent (w/w (weight/weight) or mole percent), about 60 percent (w/wor mole percent), about 75 percent (w/w or mole percent), about 80percent (w/w or mole percent), about 85 percent (w/w or mole percent),about 95 percent (w/w or mole percent) or about 99 percent (w/w or molepercent) of one amphetamine enantiomer relative to another amphetamineenantiomer (e.g., l-amphetamine relative to d-amphetamine). For example,an amphetamine composition employed in the methods can be about 80percent (w/w or mole percent) l-amphetamine or l-methamphetaminerelative to d-amphetamine or d-methamphetamine, where d-amphetamine ord-methamphetamine is about 20 percent (i.e., the remainder) (w/w or molepercent) of the amphetamine.

In another embodiment, the methods of the invention employ anamphetamine that is about 100 percent (w/w or mole percent)l-amphetamine or l-methamphetamine, wherein the l-amphetamine is acomposition that includes at least about 100 mole percent l-amphetaminerelative to a total amphetamine content of the composition or whereinthe l-methamphetamine is administered as a composition that includes atleast about 100 mole percent l-amphetamine relative to a totalamphetamine content of the composition. An amphetamine that is “about100 percent” l-amphetamine or l-methamphetamine can containinsignificant trace amounts of d-amphetamine or d-methamphetamine.

In certain preferred embodiments, particularly for those which use(R)-(−)-amphetamine (l-amphetamine) or l-methamphetamine, the kits,preparations, compositions and methods preferably use compositions of(R)-(−)-amphetamine which contain less than 10 percent (w/w or molepercent) (S)-(+)-amphetamine, and even more preferably less than lessthan 5 percent (w/w or mole percent), 1 percent (w/w or mole percent) oreven less than 0.5 percent (w/w or mole percent) (S)-(+)-amphetamine.

In another embodiment, the amphetamine employed in the methods can be apercent of the total composition administered to the human. Theamphetamine component of the composition can be about 50 percent (w/w),about 60 percent (w/w), about 75 percent (w/w), about 80 percent (w/w),about 85 percent (w/w), about 90 percent (w/w), about 95 percent (w/w)and about 100 percent (w/w) of the total composition administered to thehuman. For example, the human can be administered a composition whichcomprises about 80 weight or volume percent amphetamine and about 20weight or volume percent, respectively, inert excipient. The amphetaminecomponent of the composition includes at least one member selected fromthe group consisting of l-amphetamine, l-methamphetamine, d-amphetamineand d-methamphetamine.

In still another embodiment of the kits, preparations, compositions andmethods, the invention features one or more amphetamine compound(s)provided in an amount sufficient to enhance long-term memory in apatient by a statistically significant amount when assessed by astandardized performance test.

In certain embodiments of the kits, preparations, compositions andmethods, the invention features one or more amphetamine compound(s)comprising at least 2-fold less, or at least 4-fold less of thedistomer(s) as compared to an equally effective long term memoryenhancing dose of the distomer(s) of the amphetamine compound(s).

In certain embodiments of the kits, preparations, compositions andmethods, the invention features amphetamine comprising at least 2-foldless, or at least 4-fold less of (R)-(−)-amphetamine as compared to anequally effective long term memory enhancing dose of(S)-(+)-amphetamine.

In certain embodiments of the kits, preparations, composition andmethods, the invention features one or more amphetamine compound(s)provided in an amount sufficient to enhance long-term memory in apatient by a statistically significant amount when assessed bystandardized performance test, such as one or more of a Rey Auditory andVerbal Learning Test (RAVLT); Cambridge Neuropsychological TestAutomated Battery (CANTAB); a Children's Memory Scale (CMS); aContextual Memory Test; a Continuous Recognition Memory Test (CMRT); aDenman Neuropsychology Memory Scale; a Fuld Object Memory Evaluation(FOME); a Graham-Kendall Memory for Designs Test; a Guild Memory Test; aLearning and Memory Battery (LAMB); a Memory Assessment ClinicSelf-Rating Scale (MAC-S); a Memory Assessment Scales (MAS); a RandtMemory Test; a Recognition Memory Test (RMT); a Rivermead BehavioralMemory Test; a Russell's Version of the Wechsler Memory Scale (RWMS); aTest of Memory and Learning (TOMAL); a Vermont Memory Scale (VMS); aWechsler Memory Scale; and a Wide Range Assessment of Memory andLearning (WRAML); First-Last Name Association (Youngjohn J. R., et al.,Archives of Clinical Neuropsychology 6:287-300 (1991)); Name-FaceAssociation; Wechsler Memory Scale-Revised; (Wechsler, D., WechslerMemory Scale-Revised Manual, NY, N.Y., The Psychological Corp. (1987));California Verbal Learning Test-Second Edition (Delis, D. C., et al.,The Californian Verbal Learning Test, Second Edition, Adult Version,Manual, San Antonio, Tex.: The Psychological Corporation (2000)); FacialRecognition (delayed non-matching to sample); Cognitive Drug Research(CDR) Computerized Assessment Battery-Wesnes; Buschke's SelectiveReminder Test (Buschke, H., et al., Neurology 24:1019-1025 (1974));Telephone Dialing Test; and Brief Visuospatial Memory Test-Revised. Incertain embodiments, the methods of the invention and pharmaceuticalcomposition features one or more amphetamine compounds provided in anamount sufficient to enhance long-term memory (to improve memoryconsolidation in a human) when assessed by a word recall test such asRAVLT.

In one embodiment of the kits, preparations, compositions and methods,the invention features one or more amphetamine compound(s) provided inan amount sufficient to enhance long-term memory in a patient by astatistically significant amount when assessed by a ProvidenceRecognition Memory Test.

In another embodiment of the kits, preparations, compositions andmethods, the invention features one or more amphetamine compound(s)provided in the form of a saccharate, a sulfate or an aspartate.

In certain embodiments, the subject pharmaceutical preparations areformulated for variable dosing, and preferably to deliver a sustainedand increasing dose, e.g., over at least 4 hours, and more preferablyover at least 8 or even 16 hours. For instance, the amphetamine compoundis contained within a nonabsorbable shell that releases the drug at acontrolled rate.

In certain escalating dose formulations, the amphetamine compound(s) areformulated in a delivery system including a multiplicity of layers eachincluding the same or different polymers, a dose of the amphetaminecompound(s) in an increasing dose in the multiplicity of layers, whereinin operation the preparation delivers an increasing dose of theamphetamine compound(s) over time.

In other embodiments of escalating dose formulations, the amphetaminecompound(s) are formulated in a delivery system including a bioerodiblepolymer, a dose of the amphetamine compound(s) present in an initialdose and a final dose, whereby the preparation delivers an initial dosethen a final dose over time.

In still other embodiments of escalating dose formulations, theamphetamine compound(s) are formulated in a delivery system including aplurality of beads, each bead including a amphetamine compound andhaving a dissolution profile, which plurality of beads is a variegatedpopulation with respect to dose and/or dissolution profile so as todeliver, upon administration, said sustained and increasing dose over atleast 4 hours.

In certain escalating dose formulations, the amphetamine compound(s) areformulated in a delivery system wherein the amphetamine compound is (i)contained within a nonabsorbable shell that releases the drug at acontrolled rate, and (ii) formulated in at least two differentdissolution profiles.

In another embodiment of the kits, preparations, compositions andmethods, the invention further features a neuronal growth factor, aneuronal survival factor, a neuronal trophic factor, a cholinergicmodulator, an adrenergic modulator, a nonadrenergic modulator, adopaminergic modulator, a glutaminergic modulator or an agent thatmodulates PKC, PKA, GABA, NMDA, cannabinoid, AMPA, kainate,phosphodiesterase (PDE), CREB or nootropic pathways. In one embodiment,the modulation is a stimulation of one or more of the above-referencedpathways. In another embodiment, the modulation is an antagonism of oneor more of the above-referenced pathways. In yet another embodiment ofthe kits, preparations, compositions and methods, the invention furtherfeatures methylphenidate.

Another aspect of the invention features the use of the pharmaceuticalcomposition of amphetamine compounds in the manufacture of a medicamentfor prophylaxis or treatment of an animal susceptible to or sufferingfrom anxiety, depression, age-associated memory impairment, minimalcognitive impairment, amnesia, dementia, learning disabilities, memoryimpairment associated with toxicant exposure, brain injury, brainaneurysm, Parkinson's disease, head trauma, Huntington's disease, Pick'sdisease, Creutzfeldt-Jakob disease, stroke, schizophrenia, epilepsy,Multiple Sclerosis, mental retardation, Alzheimer's disease, age,age-associated memory impairment, Mild Cognitive Impairment, attentiondeficit disorder, attention deficit hyperactivity disorder, AnteriorCommunicating Artery Syndrome or AIDS-related dementia, whichamphetamine compound is represented by Formula I, or a pharmaceuticallyacceptable salt, solvate, metabolite or pro-drug thereof:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl;    -   R₂ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₃ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, selected from the group consisting of hydrogen,        halogen, hydroxy, alkoxy, amino, alkylamino, sulfhydryl,        alkylthio, cyano, nitro, ester, ketone, formyl, amido,        acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonate ester,        amidino, sulfonyl, sulfoxido, sulfamoyl, and sulfonamido.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 2 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In most preferred embodiments, R₁, independently and for eachoccurrence, represents hydrogen, R₂ represents methyl, and R₃ and R₄independently and for each occurrence represent hydrogen.

Another aspect of the invention features the use of an amphetaminecompound in the manufacture of a medicament for prophylaxis or treatmentof an animal susceptible to or suffering from anxiety, depression,age-associated memory impairment, minimal cognitive impairment, amnesia,dementia, learning disabilities, memory impairment associated withtoxicant exposure, brain injury, brain aneurysm, Parkinson's disease,head trauma, Huntington's disease, Pick's disease, Creutzfeldt-Jakobdisease, stroke, schizophrenia, epilepsy, Multiple Sclerosis, mentalretardation, Alzheimer's disease, age, attention deficit disorder,attention deficit hyperactivity disorder, Anterior Communicating ArterySyndrome, age-associated memory impairment, Mild Cognitive Impairment,or AIDS-related dementia, which amphetamine compound is represented byFormula II:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl;    -   R₂ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₃ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, selected from the group consisting of hydrogen,        halogen, hydroxy, alkoxy, amino, alkylamino, sulfhydryl,        alkylthio, cyano, nitro, ester, ketone, formyl, amido,        acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonate ester,        amidino, sulfonyl, sulfoxido, sulfamoyl, and sulfonamido; and    -   L is a non-toxic organic or inorganic acid.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 2 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In most preferred embodiments, R₁, independently and for eachoccurrence, represents hydrogen, R₂ represents methyl, and R₃ and R₄independently and for each occurrence represent hydrogen.

Another aspect of the invention features the use of an amphetaminecompound in the manufacture of a medicament for prophylaxis or treatmentof an animal susceptible to or suffering from anxiety, depression,age-associated memory impairment, minimal cognitive impairment, amnesia,dementia, learning disabilities, memory impairment associated withtoxicant exposure, brain injury, brain aneurysm, Parkinson's disease,head trauma, Huntington's disease, Pick's disease, Creutzfeldt-Jakobdisease, stroke, schizophrenia, epilepsy, mental retardation,Alzheimer's disease, age, age-associated memory impairment, MildCognitive Impairment, attention deficit disorder, attention deficithyperactivity disorder, Multiple Sclerosis, Anterior CommunicatingArtery Syndrome or AIDS-related dementia, which amphetamine compound isrepresented by Formula III:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₂ represents hydrogen or lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₃ is absent or represents hydrogen or lower alkyl, lower        alkenyl, lower alkynyl, aralkyl, aryl, heteroaralkyl,        heteroaryl, cycloalkyl, or cycloalkylalkyl, e.g., optionally        substituted by one or more substitutents such as halogen,        hydroxy, alkoxy;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, e.g., selected from hydrogen, halogen, hydroxy,        alkoxy, amino, alkylamino, sulfhydryl, alkylthio, cyano, nitro,        ester, ketone, formyl, amido, acylamino, acyloxy, lower alkyl,        lower alkenyl, sulfonate ester, amidino, sulfonyl, sulfoxido,        sulfamoyl, and sulfonamido;    -   R₅ independently for each occurrence, represents hydrogen or        hydroxy.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 2 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In most preferred embodiments, R₁, independently and for eachoccurrence, represents hydrogen, R₂ represents methyl, and R₃ and R₄independently and for each occurrence represent hydrogen.

Levo-amphetamine, l-amphetamine and (R)-(−)-amphetamine are usedinterchangeably herein. Levo-methamphetamine, l-methamphetamine and(R)-(−)-methamphetamine are used interchangeably herein.

In one embodiment, the (R)-(−)-amphetamine employed in the methods ofthe invention has the structural formula:

Formula IV is also referred to herein as C105, levo-amphetamine sulfateor l-amphetamine sulfate. Formula IV has the molecular formulaC₁₈H₂₈N₂O₄S and a molecular weight of 368.50. The IUPAC chemical name ofFormula IV is (−)-1-methyl-2-phenylethylamine sulfate (2:1) and the CASchemical name (−)-α-methylphenethylamine sulfate (2:1).

In another embodiment, the (R)-(−)-amphetamine employed in the methodsof the invention has the structural formula:

Formula V is also referred to herein as SN522-HCl (hydrochloride),levo-methamphetamine HCl or l-methamphetamine HCl. Formula V has themolecular formula C₁₀H₁₆NCl.

In still another embodiment, the (R)-(−)-amphetamine employed in themethods of the invention has the structural formula:

Formula VI is also referred to herein as SN522, the free base of SN522,levo-methamphetamine, levo-desoxyephedrine, l-desoxyephedrine orlevmetamfetamine. Formula VI has the molecular formula C₁₀H₁₅N and amolecular weight of 149.24.

In still another embodiment, the amphetamine compounds employed in themethods of the invention can be a combination of the amphetaminecompounds described herein, e.g., Formulas IV, V and/or VI can beemployed in any combination. For example, a human having an impairmentin memory consolidation can be treated, with l-amphetamine (e.g., C105)and l-methamphetamine (e.g., SN522, SN522-HCl), either in combination orsequentially.

In certain embodiments, the animal to be treated is a mammal. In certainpreferred embodiments the animal to be treated is a human, dog, cat,cattle, horse, sheep, hog or goat.

In certain embodiments, the pharmaceutical composition is for oraladministration.

In certain other embodiments the pharmaceutical composition is atransdermal patch. In certain embodiments the transdermal patch includesone or more penetration enhancers.

In certain embodiments, the pharmaceutical composition features anamphetamine compound provided as at least about 51 percent (w/w or molepercent), about 60 percent (w/w or mole percent), about 75 percent (w/wor mole percent), about 80 percent (w/w or mole percent), about 85percent (w/w or mole percent) about 95 percent (w/w or mole percent), or99% percent (w/w or mole percent) of the eutomers relative to thedistomers of the amphetamine compound (e.g., l-amphetamine relative tod-amphetamine). In another embodiment, the amphetamine employed to treata human is about 100% l-amphetamine (w/w or mole percent).

In certain embodiments, the pharmaceutical compositions are formulatedfor variable dosing, preferably to deliver a sustained dose, e.g., overat least 4 hours and more preferably over at least 8 or even 16 hours.For instance, the amphetamine compound(s) are contained within anonabsorbable shell that releases the drug at a controlled rate.

In certain embodiments, the pharmaceutical composition features anamphetamine compound provided in an amount sufficient to enhancelong-term memory in a patient by a statistically significant amount whenassessed by a standardized performance test.

In certain embodiments, the pharmaceutical composition features one ormore amphetamine compound(s) provided in an amount sufficient to enhancelong-term memory in a patient by a statistically significant amount whenassessed by one or more of a Rey Auditory and Verbal learning Test(RAVLT), Cambridge Neuropsychological Test Automated Battery (CANTAB); aChildren's Memory Scale (CMS); a Contextual Memory Test; a ContinuousRecognition Memory Test (CMRT); a Denman Neuropsychology Memory Scale; aFuld Object Memory Evaluation (FOME); a Graham-Kendall Memory forDesigns Test; a Guild Memory Test; a Learning and Memory Battery (LAMB);a Memory Assessment Clinic Self-Rating Scale (MAC-S); a MemoryAssessment Scales (MAS); a Randt Memory Test; a Recognition Memory Test(RMT); a Rivermead Behavioral Memory Test; a Russell's Version of theWechsler Memory Scale (RWMS); a Test of Memory and Learning (TOMAL); aVermont Memory Scale (VMS); a Wechsler Memory Scale; and a Wide RangeAssessment of Memory and Learning (WRAML); First-Last Name Association(Youngjohn J. R., et al., Archives of Clinical Neuropsychology 6:287-300(1991)); Name-Face Association; Wechsler Memory Scale-Revised;(Wechsler, D., Wechsler Memory Scale-Revised Manual, NY, N.Y., ThePsychological Corp. (1987)); California Verbal Learning Test-SecondEdition (Delis, D. C., et al., The Californian Verbal Learning Test,Second Edition, Adult Version, Manual, San Antonio, Tex.: ThePsychological Corporation (2000)); Facial Recognition (delayednon-matching to sample); Cognitive Drug Research (CDR) ComputerizedAssessment Battery-Wesnes; Buschke's Selective Reminder Test (Buschke,H., et al., Neurology 24:1019-1025 (1974)); Telephone Dialing Test; andBrief Visuospatial Memory Test-Revised.

In certain embodiments, the pharmaceutical composition features one ormore amphetamine compound(s) provided in an amount sufficient to enhancelong-term memory in a patient by a statistically significant amount whenassessed by a word recall test such as the Rey Auditory and VerbalLearning Test (RAVLT).

In certain embodiments, the pharmaceutical composition features one ormore amphetamine compound(s) provided in the form of a saccharate, asulfate or an aspartate.

In other embodiments of the kits, preparations, compositions andmethods, the invention further features amphetamine compound(s) beingprovided as a single oral dosage formulation in an amount sufficient toenhance long-term memory in a patient but resulting in a concentrationin the patient lower than its EC₅₀ as a CNS stimulant.

In other embodiments of the kits, preparations, compositions andmethods, the invention further features amphetamine compound(s) beingprovided for treating and/or preventing memory impairment (impairment inmemory consolidation, impairment in short term memory), wherein thememory impairment results from one or more of anxiety, depression,age-associated memory impairment, minimal cognitive impairment, amnesia,dementia, learning disabilities, memory impairment associated withtoxicant exposure, brain injury, brain aneurysm, Parkinson's disease,head trauma, Huntington's disease, Pick's disease, Creutzfeldt-Jakobdisease, stroke, schizophrenia, epilepsy, mental retardation,Alzheimer's disease, age, age-associated memory impairment, MildCognitive Impairment, attention deficit disorder, attention deficithyperactivity disorder, Multiple Sclerosis, Anterior CommunicatingArtery Syndrome or AIDS-related dementia.

In yet another embodiment, the invention is a method of treating aperimenopausal, menopausal or postmenopausal woman having an impairmentin memory (impairment in memory consolidation, impairment in short termmemory) with an amphetamine compound of the invention (l-amphetamime,C105, l-methamphetamine, SN522, SN522-HCl). The amphetamine compound ofthe invention can be administered to the perimenopausal, menopausal orpostmenopausal woman simultaneously or sequentially with othercompounds, drugs or agents. For example, the amphetamine compounds canbe administered to a perimenopausal, menopausal or postmenopausal womanundergoing steroid hormone replacement therapy and/or treatment fordepression (e.g., selective serotonin reuptake inhibitors such ascitalopram (Cipramil®), fluoxetine (Prozac®), fluvoxamine (Faverin®),paroxetine (Seroxat®), and sertraline (Lustral®).

In other embodiments of the kits, preparations, compositions andmethods, the invention further features amphetamine compound(s) beingprovided for enhancing memory in normal individuals.

In certain preferred embodiments of the kits, preparations, compositionsand methods, the invention features one or more amphetamine compound(s),wherein the amphetamine compound is (R)-(−)-amphetamine.

In certain preferred embodiments of the kits, preparations, compositionsand methods, the invention features one or more amphetamine compound(s),wherein the amphetamine compound is (R)-(−)-methamphetamine.

In one embodiment of the kits, preparations, compositions and methods,the invention features a single oral dosage formulation of at leastabout 2.5 mg to about 25 mg, about 50 mg, about 75 mg, about 100 mg orabout 125 mg of an amphetamine compound (e.g., l-amphetamine, C105,1-methamphetamine, SN522, SN522-HCl) and a pharmaceutically acceptablecarrier.

In another embodiment, the single dosage formulation is at least about0.001 mg, about 0.01 mg, about 0.1 mg, about 1 mg, about 2.5 mg, about 5mg, about 10 mg, about 15 mg, about 20 mg, about 25 mg, about 30 mg,about 35 mg, about 40 mg, about 45 mg, about 50 mg, about 55 mg, about60 mg, about 75 mg, about 80 mg, about 85 mg, about 90 mg, about 95 mg,about 100 mg, about 125 mg, about 150 mg, about 200 mg, about 300 mg,about 400 mg, about 500 mg, about 750 mg, or about 1000 mg of anamphetamine compound (e.g., l-amphetamine, C105, l-methamphetamine,SN522, SN522-HCl).

In still another embodiment, the methods of the invention employmultiple doses of an amphetamine compound. Each dose of the multipledose is at least about 0.001 mg, about 0.01 mg, about 0.1 mg, about 1mg, about 2.5 mg, about 5 mg, about 10 mg, about 15 mg, about 20 mg,about 25 mg, about 30 mg, about 35 mg, about 40 mg, about 45 mg, about50 mg, about 55 mg, about 60 mg, about 75 mg, about 80 mg, about 85 mg,about 90 mg, about 95 mg, about 100 mg, about 125 mg, about 150 mg,about 200 mg, about 300 mg, about 400 mg, about 500 mg, about 750 mg orabout 1000 mg of an amphetamine compound (e.g., l-amphetamine, C105,l-methamphetamine, SN522, SN522-HCl). The multiple doses can beadministered for a day, days, a week, weeks, a month, months or years.

The amphetamine compounds of the invention can be administered to ahuman acutely (briefly or short-term) or chronically (prolonged orlong-term). For example, the amphetamine compounds, (e.g.,l-amphetamine, C105, l-methamphetamine, SN522, SN522-HCl) of theinvention can be used in methods to treat a human by administering theamphetamine to the human once a day, multiple times (e.g., 2, 3, 4) in aday, for a day, days, a week, weeks, a month, months or years.

In yet another embodiment of the kits, preparations, compositions andmethods, the invention features a single oral dosage formulation ofbetween about 0.001 mg to about 125 mg; between about 0.001 mg to about250 mg; between 0.001 mg to 500 mg; or between about 0.01 mg to about125 mg; or between about 0.1 mg to about 125 mg; or between about 1 mgto about 125 mg; or between about 1 mg to about 250 mg; or between about1 mg to about 500 mg; or between about 1 mg to about 1000 mg; or betweenabout 2.5 mg to about 25 mg, about 50 mg, about 75 mg, about 100 mg orabout 125 mg of the eutomer(s) of amphetamine compound(s)(l-amphetamine, C105, 1-methamphetamine, SN522) and, optionally, apharmaceutically acceptable carrier.

In a further embodiment, the methods of the invention employ multipledoses between about 0.001 mg to about 500 mg of the amphetamine compound(e.g., l-amphetamine, C105, 1-methamphetamine, SN522, SN522-HCl),wherein each of the multiple doses of the amphetamine compound isbetween about 0.001 mg to about 125 mg; or between about 0.001 mg toabout 250 mg; or between about 0.001 mg to about 500 mg; or betweenabout 0.01 mg to about 125 mg; or between about 0.01 mg to about 500 mg;or between about 0.1 mg to about 125 mg; or between about 1 mg to about125 mg; or between about 1 mg and about 500 mg; or between about 2.5 mgto about 25 mg, about 50 mg, about 75 mg, about 100 mg, about 125 mg,about 250 mg, about 500 mg, about 750 mg, about 1000 mg of theeutomer(s) of amphetamine compound(s) (l-amphetamine, C105,l-methamphetamine, SN522, SN522-HCl) and, optionally, a pharmaceuticallyacceptable carrier.

In a further embodiment, the methods of the invention employ a singledose of the amphetamine compound (l-amphetamine, C105,1-methamphetamine, SN522, SN522-HCl) between about 0.0015 mg/kg to about2 mg/kg; or between about 0.015 mg/kg to about 2 mg/kg.

In yet another embodiment, the methods of the invention employ a singledose about 0.04 mg/kg, about 0.07 mg/kg, about 0.15 mg/kg, about 0.20mg/kg, about 0.40 mg/kg, about 0.65 mg/kg, about 1 mg/kg, about 1.50mg/kg, about 1.80 mg/kg or about 3.5 mg/kg of l-amphetamine, C105,l-methamphetamine, SN522, SN522-HCl.

In an additional embodiment, the methods of the invention employmultiple doses of the amphetamine compound (l-amphetamine, C105,l-methamphetamine, SN522, SN522-HCl), wherein each dose of the multipledose is between about 0.0015 mg/kg to about 2 mg/kg; or between about0.015 mg/kg to about 2 mg/kg.

In still another embodiment, the methods of the invention employmultiple doses, wherein each does of the multiple dose is about 0.04mg/kg, about 0.07 mg/kg, about 0.15 mg/kg, about 0.20 mg/kg, about 0.40mg/kg, about 0.65 mg/kg, about 1 mg/kg, about 1.50 mg/kg, about 1.80mg/kg or about 3.5 mg/kg of l-amphetamine, C105, l-methamphetamine,SN522, SN522-HCl.

The cumulative dose of the amphetamine compound (l-amphetamine, C105,l-methamphetamine, SN522, SN522-HCl) employed in the methods of theinvention, regardless of whether the amphetamine is administered in asingle dose or in multiple doses is between about 0.2 mg to about 250mg; or between about 1 mg to about 1250 mg of the amphetamine compound.In a particular embodiment, the cumulative dose is about 2 mg, about 10mg, about 20 mg, about 30 mg, about 50 mg, about 60 mg, about 90 mg,about 100 mg, about 150 mg, about 200 mg, about 250 mg, about 450 mg,about 750 mg, about 1000 mg, about 1250 mg, about 2500 mg or about 5000mg.

In certain embodiments, the invention features a method for enhancingmemory in an animal, a method of treating a human with an impairment inmemory consolidation or an impairment in short term memory comprisingadministering to the animal a composition of an amphetamine compound inan amount sufficient to enhance long-term memory or improve memoryconsolidation in the animal (human), wherein the composition includes atleast about 51 percent (w/w or mole percent), about 60 percent (w/w ormole percent), about 75 percent (w/w or mole percent), about 80 percent(w/w or mole percent), about 85 percent (w/w or mole percent), about 95percent (w/w or mole percent), about 99 percent (w/w or mole percent) ofthe eutomers relative to the distomers of the amphetamine or about 100%(w/w or mole percent) of compound represented by Formula I, orpharmaceutically acceptable salt, solvate, metabolite or pro-drugthereof, relative to the distomer of that amphetamine compound:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl;    -   R₂ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₃ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, selected from the group consisting of hydrogen,        halogen, hydroxy, alkoxy, amino, alkylamino, sulfhydryl,        alkylthio, cyano, nitro, ester, ketone, formyl, amido,        acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonate ester,        amidino, sulfonyl, sulfoxido, sulfamoyl, and sulfonamido.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 2 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In most preferred embodiments, R₁, independently and for eachoccurrence, represents hydrogen, R₂ represents methyl, and R₃ and R₄independently and for each occurrence represent hydrogen.

In certain embodiments, the invention features a method for enhancingmemory in an animal or a method for treating a human with an impairmentin memory consolidation, comprising administering to the animal acomposition of an amphetamine compound in an amount sufficient toenhance long-term memory or improve memory consolidation in the animal(human), wherein the composition includes at least about 51 percent (w/wor mole percent), about 60 percent (w/w or mole percent), about 75percent (w/w or mole percent), about 80 percent (w/w or mole percent),about 85 percent (w/w or mole percent, about 95 percent (w/w or molepercent), or about 99 percent (w/w or mole percent) of the eutomersrelative to the distomers of the amphetamine compound, wherein theamphetamine compound is a pharmaceutically acceptable salt representedby Formula II:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl;    -   R₂ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₃ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, selected from the group consisting of hydrogen,        halogen, hydroxy, alkoxy, amino, alkylamino, sulfhydryl,        alkylthio, cyano, nitro, ester, ketone, formyl, amido,        acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonate ester,        amidino, sulfonyl, sulfoxido, sulfamoyl, and sulfonamido; and    -   L is a non-toxic organic or inorganic acid.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 2 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In most preferred embodiments, R₁, independently and for eachoccurrence, represents hydrogen, R₂ represents methyl, and R₃ and R₄independently and for each occurrence represent hydrogen.

In certain embodiments, the invention features a method for enhancingmemory in an animal or a method of treating a human with an impairmentin memory consolidation, comprising administering to the animal acomposition of an amphetamine compound in an amount sufficient toenhance long-term memory or improve memory consolidation in the animal(human), wherein the composition includes at least about 51 percent (w/wor mole percent), about 60 percent (w/w or mole percent), about 75percent (w/w or mole percent), about 80 percent (w/w or mole percent),about 85 percent (w/w or mole percent), about 95 percent (w/w or molepercent), or about 99 percent (w/w or mole percent) of the eutomersrelative to the distomers of the amphetamine compound, wherein theamphetamine compound is an amphetamine metabolite represented by FormulaIII, or pharmaceutically acceptable salt, solvate, or pro-drug thereof:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₂ represents hydrogen or lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₃ represents hydrogen or lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, e.g., selected from hydrogen, halogen, hydroxy,        alkoxy, amino, alkylamino, sulfhydryl, alkylthio, cyano, nitro,        ester, ketone, formyl, amido, acylamino, acyloxy, lower alkyl,        lower alkenyl, sulfonate ester, amidino, sulfonyl, sulfoxido,        sulfamoyl, and sulfonamido;    -   R₅ independently for each occurrence, represents hydrogen or        hydroxy.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents hydrogen, or loweralkyl; R₂ represents hydrogen or lower alkyl, R₃ represents hydrogen orlower alkyl, and R₄ represents hydrogen or from 1 to 2 substituents onthe ring to which it is attached, selected from halogen,trifluoromethyl, hydroxy, amino, cyano, nitro, and lower alkyl.

In certain preferred embodiments, R₄ represents hydrogen and at leastone of R₁, R₂, and R₃ represents hydrogen.

In certain preferred embodiments, R₄ represents hydrogen and at leasttwo of R₁, R₂, and R₃ represent hydrogen.

In certain preferred embodiments, both occurrences of R₁ representindependently hydrogen, R₂ represents methyl, R₃ represents hydrogen andR₄ represents hydrogen.

In certain preferred embodiments, one occurrence of R₁ representshydrogen, the second occurrence of R₁ represents methyl, R₂ representsmethyl, R₃ represents hydrogen and R₄ represents hydrogen.

In most preferred embodiments, R₁, independently and for eachoccurrence, represents hydrogen, R₂ represents methyl, and R₃ and R₄independently and for each occurrence represent hydrogen.

In certain embodiments, the invention features a kit comprising anamphetamine compound formulation, e.g., as described herein andpreferably provided in single oral dosage form or as a transdermal patchfor enhancing memory in a patient (preferably a human), and inassociation with instructions (written and/or pictorial) describing theuse of the formulation for enhancing memory, and optionally, warnings ofpossible side effects and drug-drug or drug-food interactions.

Another aspect of the invention relates to a method for conducting apharmaceutical business, which includes: (a) manufacturing the kits,preparations, and compositions of the present invention; and (b)marketing to healthcare providers the benefits of using the kits,preparations, and compositions of the present invention to enhancememory of treated patients.

Another aspect of the invention relates to a method for conducting apharmaceutical business, comprising: (a) providing a distributionnetwork for selling the kits, preparations, and compositions of thepresent invention; and (b) providing instruction material to patients orphysicians for using the kits, preparations, and compositions of thepresent invention to enhance memory of treated patients.

Yet another aspect of the invention relates to a method for conducting apharmaceutical business, comprising: (a) determining an appropriatedosage of an amphetamine compound to enhance memory function in a classof patients; (b) conducting therapeutic profiling of one or moreformulations of the amphetamine compound identified in step (a), forefficacy and toxicity in animals; and (c) providing a distributionnetwork for selling the formulations identified in step (b) as having anacceptable therapeutic profile.

For instance, the subject business method can include an additional stepof providing a sales group for marketing the preparation to healthcareproviders.

Another aspect of the invention relates to a method for conducting apharmaceutical business, comprising: (a) determining an appropriatedosage of an amphetamine compound to enhance memory function in a classof patients; and (b) licensing, to a third party, the rights for furtherdevelopment and sale of the amphetamine compound for enhancing memory.

In certain embodiments of the method, the class of patients suffer frommemory impairment. In preferred embodiments of the method, the memoryimpairment results from one or more of anxiety, depression,age-associated memory impairment, minimal cognitive impairment, amnesia,dementia, learning disabilities, memory impairment associated withtoxicant exposure, brain injury, brain aneurysm, Parkinson's disease,head trauma, Huntington's disease, Pick's disease, Creutzfeldt-Jakobdisease, stroke, schizophrenia, epilepsy, mental retardation,Alzheimer's disease, age, age-associated memory impairment, MildCognitive Impairment, attention deficit disorder, attention deficithyperactivity disorder, Multiple Sclerosis, Anterior CommunicatingArtery Syndrome or AIDS-related dementia. In other preferred embodimentsof the method, the class of patients are normal individuals.

Another aspect of the invention features solid dosage form comprising aeutomer of an amphetamine compound represented by Formula I, or apharmaceutically acceptable salt, solvate, metabolite or pro-drugthereof, in an amount of 25 mg or less:

-   -   wherein, as valence and stability permit,    -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl;    -   R₂ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₃ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, selected from the group consisting of hydrogen,        halogen, hydroxy, alkoxy, amino, alkylamino, sulfhydryl,        alkylthio, cyano, nitro, ester, ketone, formyl, amido,        acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonate ester,        amidino, sulfonyl, sulfoxido, sulfamoyl, and sulfonamido.

Another aspect of the invention features solid dosage form comprising apharmaceutically acceptable salt of a eutomer of an amphetamine compoundemployed in the methods of the invention, for example, represented byFormula II, solvate, metabolite or pro-drug thereof, in an amount of 25mg or less:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl;    -   R₂ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₃ represents hydrogen or substituted or unsubstituted lower        alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,        heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, selected from the group consisting of hydrogen,        halogen, hydroxy, alkoxy, amino, alkylamino, sulfhydryl,        alkylthio, cyano, nitro, ester, ketone, formyl, amido,        acylamino, acyloxy, lower alkyl, lower alkenyl, ester, amidino,        sulfonyl, sulfoxido, sulfamoyl, and sulfonamido; and    -   L is a non-toxic organic or inorganic acid.

Another aspect of the invention features solid dosage form comprising aeutomer of an amphetamine metabolite represented by Formula III, solvateor pro-drug thereof, in an amount of about 25 mg or less:

wherein, as valence and stability permit,

-   -   R₁, independently for each occurrence, represents hydrogen or        substituted or unsubstituted lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₂ represents hydrogen or lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₃ represents hydrogen or lower alkyl, lower alkenyl, lower        alkynyl, aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl,        or cycloalkylalkyl, e.g., optionally substituted by one or more        substitutents such as halogen, hydroxy, alkoxy;    -   R₄ represents from 1 to 3 substituents on the ring to which it        is attached, e.g., selected from hydrogen, halogen, hydroxy,        alkoxy, amino, alkylamino, sulfhydryl, alkylthio, cyano, nitro,        ester, ketone, formyl, amido, acylamino, acyloxy, lower alkyl,        lower alkenyl, sulfonate ester, amidino, sulfonyl, sulfoxido,        sulfamoyl, sulfonamido;    -   R₅ independently for each occurrence, represents hydrogen or        hydroxy.

The practice of the present invention will employ, unless otherwiseindicated, conventional techniques of synthetic chemistry, organicchemistry, inorganic chemistry, organometallic chemistry, pharmaceuticalchemistry, and behavioral science, which are within the skill of theart. Such techniques are described in the literature. See, for example,Advanced Organic Chemistry: Reactions, Mechanisms, And Structure by J.March (John Wiley and Sons, N.Y., 1992); The Chemist's Companion: AHandbook Of Practical Data, Techniques, And References by A. J. Gordonand R. A. Ford (Wiley, NY, 1972); Synthetic Methods Of OrganometallicAnd Inorganic Chemistry by W. A. Herrmann and Brauer (Georg ThiemeVerlag, N.Y., 1996); Experimental Organic Chemistry by D. Todd(Prentice-Hall, N.J., 1979); Experimental Organic Chemistry: StandardAnd Microscale by L. M. Harwood (Blackwell Science, M.A., 1999);Experimental Analysis Of Behavior by I. H. Iversen and K. A. Lattal(Elsevier, N.Y., 1991); A Practical Guide To Behavioral Research: ToolsAnd Techniques by R. Sommer and B. Sommer (Oxford University Press,N.Y., 2002); Advances In Drug Discovery Techniques by A. L. Harvey(Chichester, N.Y., 1998); Quantitative Calculations In PharmaceuticalPractice And Research by T. P. Hadjiioannou (VCH, N.Y., 1993); Drug FateAnd Metabolism: Methods And Techniques by E. R. Garrett and J. L. Hirtz(M. Dekker, N.Y., 1977); Behavioral Science Techniques: An AnnotatedBibliography For Health Professionals by M. K. Tichy (PraegerPublishers, N.Y., 1975).

The invention described herein provides methods of treating a humanhaving an impairment in memory consolidation or impairment in short termmemory. Advantages of the claimed invention include, for example, thetreatment of humans suffering an impairment in memory consolidation in acost effective manner and without significant side affects, especiallyin individuals who have had a condition or disease for an extendedperiod of time and where clinical management strategies are difficult toimplement. Of particular importance, are conditions which requirelong-term treatment where addictive and potent side effects would beconsiderably undesirable. The claimed methods provide an efficient wayto treat and reduce the severity of an impairment in memoryconsolidation in humans.

Thus, treatment with l-amphetamine (e.g., C105) or l-methamphetamine(e.g., SN522, SN522-HCl) can halt, reverse or diminish the progressionof the impairment in memory consolidation, thereby increasing thequality of life without adverse side affects, such as addiction,alterations in blood pressure and heart rate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents the effectiveness of various doses of S-(+)-amphetamineon Performance in the Inhibitory Avoidance Task.

FIG. 2 demonstrates the effect of 2 mg/kg of S-(+)-amphetamine onPerformance in the Inhibitory Avoidance Task.

FIG. 3 shows the varying effect of S-(+)-amphetamine depending on thetime between administration and inception of training.

FIG. 4 illustrates the effect of S-(+)-amphetamine on memory retentionone week after the initial training.

FIG. 5 depicts the effects of S-(+)-amphetamine on normal andfornix-lesioned animals.

FIG. 6 shows the effect of S-(+)-amphetamine (2.0 mg/kg) on Performancein Inhibitory Avoidance.

FIGS. 7A, 7B, 7C, 7D, 7E and 7F show the effect of S-(+)-amphetamine onActivity Levels.

FIG. 8 shows the effectiveness of various doses of R-(−)-amphetamine onmemory retention.

FIG. 9 shows the effectiveness of R-(−)-amphetamine on memory retention.

FIG. 10 shows the effect of R-(−)-amphetamine (0.5 mg/kg) on Performancein the Inhibitory Avoidance Task.

FIG. 11 shows the effect of Post Training Administration ofR-(−)-amphetamine (0.5 mg/kg) on Performance in the Inhibitory AvoidanceTask.

FIG. 12 shows the effect of R-(−)-amphetamine (1.0 mg/kg) on InhibitoryAvoidance Performance in Fornix Lesion Rats.

FIGS. 13A, 13B, 13C and 13D show the effect of R-(−)-amphetamine onPerformance in the Object Recognition Task in Normal and Formix LesionRats.

FIGS. 14 A, 14B, 14C, 14D, 14E and 14F show the effect ofR-(−)-amphetamine (0.5 mg/kg) on Activity Levels.

FIGS. 15A, 15B, 15C, 15D, 15E and 15F shows the effect ofS-(+)-amphetamine (2 mg/kg) on Activity Levels.

FIG. 16 shows the effect of R-(−)-amphetamine on Tail-Flick Analgesia.

FIG. 17 shows an exemplary sustained release device.

FIG. 18 depicts the pharmacokinetics of R-(−)-amphetamine and MemoryAssessments and PK.

FIG. 19 shows that administration of R-(−)-amphetamine to human patientscan improve verbal memory.

FIG. 20 depicts the Step-Through Latency (sec) for rats treated withcontrol/vehicle (veh), d-amphetamine (d-amph), l-amphetamine (C105) orl-methamphetamine (SN522).

FIG. 21 depicts the Step-Through Latency (sec) for rats treated withcontrol (O) or varying doses of l-methamphetamine (SN522). The asteriskindicates a significant difference from the control (p<0.05).

FIG. 22 depicts the Escape Latency (sec) for rats treated with salinecontrol or l-methamphetamine (SN522).

FIG. 23 depicts the Activity Measure (% increase from control) for ratstreated with l-methamphetamine (SN522).

FIG. 24 depicts the Activity Measure (% increase from control) for ratstreated with D-amphetamine (d-amph).

FIG. 25 depicts the Memory Score, as assessed by the Rey Auditory andVerbal Learning Test, following a 30 minute (min) and a 24 hour (hr)recall time for humans treated with l-amphetamine (C105). The asteriskdepicts significant differences.

FIG. 26 compares individual subject's memory scores, as assessed by theRey Auditory and Verbal Learning Test (RAVLT Score (0-15)), followingplacebo treatment to their best score following treating withl-amphetamine (C105).

DETAILED DESCRIPTION OF THE INVENTION

The features and other details of the invention, either as steps of theinvention or as combinations of parts of the invention, will now be moreparticularly described and pointed out in the claims. It will beunderstood that the particular embodiments of the invention are shown byway of illustration and not as limitations of the invention. Theprincipal features of this invention can be employed in variousembodiments without departing from the scope of the invention.

The present invention relates to the discovery that the amphetamineclass of compounds (collectively referred to herein as “amphetaminecompounds”) can be used to enhance and/or restore long-term memoryfunction and performance, e.g., to improve long-term memory (LTM) inanimal subjects. More particularly, the invention relates to thediscovery that particular stereoisomers of amphetamine compounds are themost effective for therapeutic use. The amphetamine compounds of theinvention (e.g., R-(−)-amphetamine and R-(−)-methamphetamine) improvememory consolidation (the process of storing new information inlong-term memory) in a human.

Furthermore, the present invention relates to the discovery that theamphetamine compounds can be used to enhance and/or restore attentionspan and/or focus in animal subjects. The compounds can be useful inimproving the attention span of normal individuals, as well as improvingthe attention span of individuals characterized by a deficit inattention span and/or focus (eg, individuals diagnosed with an attentiondeficit disorder). Lack of attentiveness may lead to a failure toprocess new information and accordingly commit such new information tomemory. Lack of focus may also lead to difficulties in later recallingpreviously processed information. Thus, deficits in attentiveness and/orfocus may affect learning and memory. In addition to memory and learningdifficulties, lack of attentiveness has many other negative social andbehavioral consequences. Accordingly, the subject amphetamine compoundsmay be used to enhance and/or restore at least one of memory, learning,attentiveness, or focus.

Amphetamine is a nervous system stimulant that may mildly increase bloodpressure and decreases appetite. Abuse of amphetamine has been shown tocause severe side effects including dependence and possibly inducedpsychosis. Amphetamine is synonymous with actedron; actemin; adderall;adipan; akedron; allodene; alpha-methyl-(±)-benzeneethanamine;alpha-methylbenzeneethanamine; alpha-methylphenethylamine; amfetamine;amphate; anorexine; benzebar; benzedrine; benzyl methyl carbinamine;benzolone; beta-amino propylbenzene; beta-phenylisopropylamine;biphetamine; desoxynorephedrine; dietamine; DL-amphetamine; elastonon;fenopromin; finam; isoamyne; isomyn; mecodrin; monophos; mydrial;norephedrane; novydrine; obesin; obesine; obetrol; octedrine; oktedrin;phenamine; phenedrine; phenethylamine, alpha-methyl-; percomon;profamina; profetamine; propisamine; racephen; raphetamine; rhinalator;sympamine; simpatedrin; simpatina; sympatedrine; and weckamine.

The present invention contemplates, in part, the use of an amphetaminecomposition which is enriched for eutomers of amphetamine compounds. Inparticular, the use of pharmaceutical preparations for improving memoryconsolidation in humans, include (R)-(−)-amphetamine or a derivativethereof. (R)-(−)-amphetamine (l-amphetamine, levo-amphetamine, C105) iseffective at a dose one-fourth (¼) the dose of the (S)-(+) enantiomer(d-amphetamine, dexo-amphetamine) of amphetamine. In addition, unlike(S)-(+)-amphetamine, the (R)-(−) enantiomer has not been shown to beaddictive and does not produce undesirable side effects such asincreased activity, increased blood pressure or increased heart rate.

In certain embodiments, a mixture of enantiomers of the subjectcompounds may be employed, e.g., a racemic mixture containing bothenantiomers of a chosen compound, e.g., with each enantiomer beingpresent in equal amounts, or in differing amounts. In certainembodiments, the therapeutic preparation may be enriched to providepredominantly one enantiomer of a subject compound. In one embodiment,an enantiomerically enriched mixture can comprise an amphetaminecompound that is at least about 51 w/w or mole percent, about 60 w/w ormole percent, about 75 w/w or mole percent, about 80 w/w or molepercent, about 85 w/w or mole percent, about 90 w/w or mole percent,about 95 w/w or mole percent or about 99 w/w or mole percentl-amphetamine relative to d-amphetamine. In another embodiment, theamphetamine compound employed in the methods is about 100 w/w or molepercent l-amphetamine. In preferred embodiments, the amphetaminecompound provided in the formulation is at least about 60 percent (w/wor mole percent) of the eutomer relative to the distomer of theamphetamine compound, and more preferably at least about 75 w/w or molepercent, about 80 w/w or mole percent, about 85 w/w or mole percent,about 90 w/w or mole percent, about 95 w/w or mole percent or about 99w/w or mole percent. Furthermore, the present invention is based onusing the subject compounds for enhancing or restoring attention spanand/or focus. The effects of the subject compounds on attention span mayhave secondary consequences on the ability to process and/or recallinformation, and therefore may also enhance memory and/or learning.

The amphetamine compounds can also be provided in the form ofpharmaceutical salts and as prodrugs.

In certain embodiments, the method includes administering, conjointlywith the pharmaceutical preparation, one or more of a neuronal growthfactor, a neuronal survival factor, and a neuronal trophic factor.Additionally or alternatively, a subject compound may be administered inconjunction with a cholinergic, adrenergic, nonadrenergic, dopaminergic,or glutaminergic modulator. Other agents directed at modulating GABA,NMDA, cannabinoid, AMPA, kainate, phosphodiesterase (PDE), PKA, PKC,CREB or nootropic systems may be important to the improvement ofcognitive function and may be administered in conjunction with a subjectcompound. An agent to be administered conjointly with a subject compoundmay be formulated together with a subject compound as a singlepharmaceutical preparation, e.g., as a pill or other medicamentincluding both agents, or may be administered as a separatepharmaceutical preparation.

In another aspect, the present invention provides pharmaceuticalpreparations comprising, as an active ingredient, an enantiomericallyenriched preparation of R-(−)amphetamine or a derivative thereof. Theamphetamine compound is formulated in an amount sufficient to improvememory consolidation in an animal. The preparations and methods can betreatments using amphetamine compounds effective for human and/or animalsubjects. In addition to humans, other animal to which the invention isapplicable extend to both domestic animals and livestock, raised eitheras pets or for commercial purposes. Examples are dogs, cats, cattle,horses, sheep, hogs, and goats.

Still another aspect of the invention relates to the use ofenantiomerically enriched preparations of amphetamine compounds forlessening the severity or prophylactically preventing the occurrence oflearning and/or memory defects in an animal, and thus, altering thelearning ability and/or memory capacity of the animal. As a result, thecompounds of the present invention may be useful for treating and/orpreventing memory impairment, e.g., due to toxicant exposure, braininjury, brain aneurysm, age-associated memory impairment, mild cognitiveimpairment, epilepsy, mental retardation in children, and dementiaresulting from a disease, such as Parkinson's disease, Alzheimer'sdisease, AIDS, head trauma, Huntington's disease, Pick's disease,Creutzfeldt-Jakob disease, age-associated memory impairment, MildCognitive Impairment, Multiple Sclerosis, Anterior Communicating ArterySyndrome and stroke. In addition, the compounds of the invention may beuseful in enhancing memory in normal individuals.

The invention also relates to the conjoint use of an amphetaminecompound with agents that mimic or stimulate PKC and/or PKA pathways.

Definitions

For convenience, certain terms employed in the specification, examples,and appended claims are collected here.

As used herein, the term “amphetamine compounds” is meant to includeamphetamine, analogs of amphetamine, enantiomerically or isomericallyenriched amphetamine, and enantiomerically or isomerically enrichedanalogs of amphetamine, as well as pharmaceutically acceptable salts ofsuch compounds and prodrugs. In particular, amphetamine compounds of theinvention, or analogs thereof which are administered to the human havingan impairment in memory (impairment in memory consolidation, impairmentin short-term memory), include compounds having the structure as givenin Formulas I, II, III, IV, V and VI above.

The term “amphetamine,” such as is used when referring to“l-amphetamine” and “d-amphetamine,” means a compound having FormulaVII, including its salts, acids, esters, amides, carbamates, Schiffbases, prodrugs and other structural and functional derivatives thereof.In a preferred embodiment, the amphetamine is the compound representedby Formula VII including salts, acids, esters, amides, carbamates andSchiff bases. In another preferred embodiment, the amphetamine is thecompound represented by Formula VII, including its salts and acids. Instill another preferred embodiment, the amphetamine is the compound ofFormula VII:

The term “methamphetamine,” such as is used when referring to“l-methamphetamine” and “d-methamphetamine,” means a compound havingFormula VIII, including its salts, acids, esters, amides, carbamates,Schiff bases, prodrugs and other structural and functional derivativesthereof. In a preferred embodiment, the methamphetamine is the compoundrepresented by Formula VIII including salts, acids, esters, amides,carbamates and Schiff bases. In another preferred embodiment, themethamphetamine is the compound represented by Formula VIII, includingits salts and acids. In still another preferred embodiment, themethamphetamine is the compound represented by Formula VIII:

The dextro enantiomer of amphetamine is referred to in the art as the d,(+), D or S isomer and is represented by the general formula:

The levo enantiomer of amphetamine is referred to in the art as the 1,(−), L or R isomer and is represented by the general formula:

The racemic mixtures may be referred to as d,l or (+,−) or (±) or DL or(R)(S).

The term “ED₅₀” means the dose of a drug which produces 50% of itsmaximum response or effect.

An “effective amount” of, e.g., an amphetamine compound, with respect tothe subject method of treatment, refers to an amount of the activator ina pharmaceutical preparation which, when applied as part of a desireddosage regimen brings about enhanced memory (memory consolidation, shortterm memory) according to clinically acceptable standards.

The term “LD₅₀” means the dose of a drug which is lethal in 50% of testsubjects.

A “patient” or “subject” to be treated by the subject method can meaneither a human or non-human animal.

The term “prodrug” represents compounds which are rapidly transformed invivo, for example, by hydrolysis in blood into the therapeuticallyactive agents of the present invention. A common method for making aprodrug is to include selected moieties which are converted underphysiologic conditions (enzymatic or nonenzymatic) to reveal the desiredmolecule. A thorough discussion is provided in T. Higuchi and V. Stella,Pro-drugs as Novel Delivery Systems, Vol. 14 of the A.C.S. SymposiumSeries, and in Edward B. Roche, ed., Bioreversible Carriers in DrugDesign, American Pharmaceutical Association and Pergamon Press, 1987,both of which are incorporated herein by reference.

The term “therapeutic index” refers to the therapeutic index of a drugdefined as LD₅₀/ED₅₀.

By “transdermal patch” is meant a system capable of delivery of a drugto a patient via the skin, or any suitable external surface, includingmucosal membranes, such as those found inside the mouth. Such deliverysystems generally comprise a flexible backing, an adhesive and a drugretaining matrix, the backing protecting the adhesive and matrix and theadhesive holding the whole on the skin of the patient. On contact withthe skin, the drug-retaining matrix delivers drug to the skin, the drugthen passing through the skin into the patient's system.

The term “adrenergic” refers to neurotransmitters or neuromodulatorschemically related to adrenaline (epinephrine) or to neurons whichrelease such adrenergic mediators. Examples are dopamine,norepinephrine, epinephrine. Such agents are also referred to ascatecholamines, which are derived from the amino acid tyrosine.

The term “biogenic amines” refers to a class of neurotransmitters whichinclude catecholamines (e.g., dopamine, norepinephrine, and epinephrine)and serotonin.

The term “catecholamines” refers to neurotransmitters that have acatechol ring (e.g., a 3,4-dihydroxylated benzene ring). Examples aredopamine, norepinephrine, and epinephrine.

The term “cholinergic” refers to neurotransmitters or neuromodulatorschemically related to choline or to neurons which release suchcholinergic mediators.

The term “dopaminergic” refers to neurotransmitters or neuromodulatorschemically related to dopamine or to neurons which release suchdopaminergic mediators.

The term “dopamine” refers to an adrenergic neurotransmitter, as isknown in the art.

Herein, the term “aliphatic group” refers to a straight-chain,branched-chain, or cyclic aliphatic hydrocarbon group and includessaturated and unsaturated aliphatic groups, such as an alkyl group, analkenyl group, and an alkynyl group.

The terms “alkenyl” and “alkynyl” refer to unsaturated aliphatic groupsanalogous in length and possible substitution to the alkyls describedabove, but that contain at least one double or triple bond respectively.

The terms “alkoxyl” or “alkoxy” as used herein refers to an alkyl group,as defined above, having an oxygen radical attached thereto.Representative alkoxy groups include methoxy, ethoxy, propyloxy,tert-butoxy and the like. An “ether” is two hydrocarbons covalentlylinked by an oxygen. Accordingly, the substituent of an alkyl thatrenders that alkyl an ether is or resembles an alkoxyl, such as can berepresented by one of —O-alkyl, —O-alkenyl, —O-alkynyl, —O—(CH₂)_(m)—R₈,where R₈ represents an aryl, a cycloalkyl, a cycloalkenyl, a heterocycleor a polycycle; and m is zero or an integer in the range of 1 to 8

The term “alkyl” refers to the radical of saturated aliphatic groups,including straight-chain alkyl groups, branched-chain alkyl groups,cycloalkyl (alicyclic) groups, alkyl-substituted cycloalkyl groups, andcycloalkyl-substituted alkyl groups. In preferred embodiments, astraight chain or branched chain alkyl has 8 or fewer carbon atoms inits backbone (e.g., C₁-C₈ for straight chains, C₃-C₈ for branchedchains), and more preferably 5 or fewer. Likewise, preferred cycloalkylshave from 3-10 carbon atoms in their ring structure, and more preferablyhave 5, 6 or 7 carbons in the ring structure.

Moreover, the term “alkyl” (or “lower alkyl”) as used throughout thespecification, examples, and claims is intended to include both“unsubstituted alkyls” and “substituted alkyls”, the latter of whichrefers to alkyl moieties having substituents replacing a hydrogen on oneor more carbons of the hydrocarbon backbone. Such substituents caninclude, for example, a halogen, a hydroxyl, a carbonyl (such as acarboxyl, an alkoxycarbonyl, a formyl, or an acyl), a thiocarbonyl (suchas a thioester, a thioacetate, or a thioformate), an alkoxyl, aphosphoryl, a phosphate, a phosphonate, a phosphinate, an amino, anamido, an amidine, an imine, a cyano, a nitro, an azido, a sulfhydryl,an alkylthio, a sulfate, a sulfonate, a sulfamoyl, a sulfonamido, asulfonyl, a heterocyclyl, an aralkyl, or an aromatic or heteroaromaticmoiety. It will be understood by those skilled in the art that themoieties substituted on the hydrocarbon chain can themselves besubstituted, if appropriate. For instance, the substituents of asubstituted alkyl may include substituted and unsubstituted forms ofamino, azido, imino, amido, phosphoryl (including phosphonate andphosphinate), sulfonyl (including sulfate, sulfonamido, sulfamoyl andsulfonate), and silyl groups, as well as ethers, alkylthios, carbonyls(including ketones, aldehydes, carboxylates, and esters), —CF₃, —CN andthe like. Exemplary substituted alkyls are described below. Cycloalkylscan be further substituted with alkyls, alkenyls, alkoxys, alkylthios,aminoalkyls, carbonyl-substituted alkyls, —CF₃, —CN, and the like.

Unless the number of carbons is otherwise specified, “lower alkyl” asused herein means an alkyl group, as defined above, but having from oneto eight carbons, more preferably from one to five carbon atoms in itsbackbone structure. Likewise, “lower alkenyl” and “lower alkynyl” havesimilar chain lengths. Throughout the application, preferred alkylgroups are lower alkyls. In preferred embodiments, a substituentdesignated herein as alkyl is a lower alkyl.

The term “alkylthio” refers to an alkyl group, as defined above, havinga sulfur radical attached thereto. In preferred embodiments, the“alkylthio” moiety is represented by one of —S-alkyl, —S-alkenyl,—S-alkynyl, and —S—(CH₂)_(m)—R₈, wherein R₈ represents an aryl, acycloalkyl, a cycloalkenyl, a heterocycle or a polycycle; and m is zeroor an integer in the range of 1 to 8. Representative alkylthio groupsinclude methylthio, ethylthio, and the like.

The terms “amine” and “amino” are art-recognized and refer to bothunsubstituted and substituted amines, e.g., a moiety that can berepresented by the general formula:

wherein R₉ and R₁₀ each independently represent a hydrogen, an alkyl, analkenyl, —(CH₂)_(m)—R₈, or R₉ and R₁₀ taken together with the N atom towhich they are attached complete a heterocycle having from 4 to 8 atomsin the ring structure; R₈ represents an aryl, a cycloalkyl, acycloalkenyl, a heterocycle or a polycycle; and m is zero or an integerin the range of 1 to 8. In preferred embodiments, R₉ and R₁₀ eachindependently represent a hydrogen, an alkyl, an alkenyl, or—(CH₂)_(m)—R₈, wherein R₈ represents an aryl, a cycloalkyl, acycloalkenyl, a heterocycle or a polycycle; and m is zero or an integerin the range of 1 to 8. Thus, the term “alkylamine” as used herein meansan amine group, as defined above, having a substituted or unsubstitutedalkyl attached thereto, i.e., at least one of R₉ and R₁₀ is an alkylgroup.

The term “amido” is art-recognized as an amino-substituted carbonyl andincludes a moiety that can be represented by the general formula:

wherein R₉, R₁₀ are as defined above. Preferred embodiments of the amidewill not include imides which may be unstable.

The term “aralkyl”, as used herein, refers to an alkyl group substitutedwith an aryl group (e.g., an aromatic or heteroaromatic group).

The term “aryl” as used herein includes 5-, and 6-membered single-ringaromatic groups that may include from zero to four heteroatoms, forexample, benzene, pyrrole, furan, thiophene, imidazole, oxazole,thiazole, triazole, pyrazole, pyridine, pyrazine, pyridazine andpyrimidine, and the like. Those aryl groups having heteroatoms in thering structure may also be referred to as “aryl heterocycles”,“heteroaryls”, or “heteroaromatics.” The aromatic ring can besubstituted at one or more ring positions with such substituents asdescribed above, for example, halogen, azide, alkyl, aralkyl, alkenyl,alkynyl, cycloalkyl, hydroxyl, alkoxyl, amino, nitro, sulfhydryl, imino,amido, phosphate, phosphonate, phosphinate, carbonyl, carboxyl, silyl,ether, alkylthio, sulfonyl, sulfonamido, ketone, aldehyde, ester,heterocyclyl, aromatic or heteroaromatic moieties, —CF₃, —CN, or thelike. The term “aryl” also includes polycyclic ring systems having twoor more cyclic rings in which two or more carbons are common to twoadjoining rings (the rings are “fused rings”) wherein at least one ofthe rings is aromatic, e.g., the other cyclic rings can be cycloalkyls,cycloalkenyls, cycloalkynyls, aryls and/or heterocyclyls.

The term “carbocycle” or “cyclic alkyl”, as used herein, refers to anaromatic or non-aromatic ring in which each atom of the ring is carbon.

The term “carbonyl” is art-recognized and includes such moieties as canbe represented by the general formula:

wherein X is a bond or represents an oxygen or a sulfur, and R₁,represents a hydrogen, an alkyl, an alkenyl, —(CH₂)_(m)—R₈ or apharmaceutically acceptable metal or aminergic counterion, R′₁₁represents a hydrogen, an alkyl, an alkenyl or —(CH₂)_(m)—R₈, wherein R₈represents an aryl, a cycloalkyl, a cycloalkenyl, a heterocycle or apolycycle; and m is zero or an integer in the range of 1 to 8. Where Xis an oxygen and R₁₁ or R′₁₁ is not hydrogen, the formula represents an“ester”. Where X is an oxygen, and R₁₁ is as defined above, the moietyis referred to herein as a carboxyl group, and particularly when R₁₁ isa hydrogen, the formula represents a “carboxylic acid”. Where X is anoxygen, and R′₁₁ is hydrogen, the formula represents a “formate”. Ingeneral, where the oxygen atom of the above formula is replaced bysulfur, the formula represents a “thiocarbonyl” group. Where X is asulfur and R₁₁ or R′₁₁ is not hydrogen, the formula represents a“thioester.” Where X is a sulfur and R₁₁ is hydrogen, the formularepresents a “thiocarboxylic acid.” Where X is a sulfur and R₁₁′ ishydrogen, the formula represents a “thioformate.” On the other hand,where X is a bond, and R₁₁ is not hydrogen, the above formula representsa “ketone” group. Where X is a bond, and R₁₁ is hydrogen, the aboveformula represents an “aldehyde” group.

The term “heteroatom” as used herein means an atom of any element otherthan carbon or hydrogen. Preferred heteroatoms are nitrogen, oxygen andsulfur.

The terms “heterocyclyl” or “heterocyclic group” refer to 3- to10-membered ring structures, more preferably 3- to 7-membered rings,whose ring structures include one to four heteroatoms. Heterocycles canalso be polycycles. Heterocyclyl groups include, for example, thiophene,thianthrene, furan, pyran, isobenzofuran, chromene, xanthene,phenoxathiin, pyrrole, imidazole, pyrazole, isothiazole, isoxazole,pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole,indole, indazole, purine, quinolizine, isoquinoline, quinoline,phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline,pteridine, carbazole, carboline, phenanthridine, acridine, pyrimidine,phenanthroline, phenazine, phenarsazine, phenothiazine, furazan,phenoxazine, pyrrolidine, oxolane, thiolane, oxazole, piperidine,piperazine, morpholine, lactones, lactams such as azetidinones andpyrrolidinones, sultams, sultones, and the like. The heterocyclic ringcan be substituted at one or more positions with such substituents asdescribed above, as for example, halogen, alkyl, aralkyl, alkenyl,alkynyl, cycloalkyl, hydroxyl, amino, nitro, sulfhydryl, imino, amido,phosphate, phosphonate, phosphinate, carbonyl, carboxyl, silyl, ether,alkylthio, sulfonyl, ketone, aldehyde, ester, a heterocyclyl, anaromatic or heteroaromatic moiety, —CF₃, —CN, or the like.

The term “metabolites” refers to active derivatives produced uponintroduction of a compound into a biological milieu, such as a patient.

As used herein, the term “nitro” means —NO₂; the term “halogen”designates —F, —Cl, —Br or —I; the term “sulfhydryl” means —SH; the term“hydroxyl” means —OH; and the term “sulfonyl” means —SO₂—.

The terms “polycyclyl” or “polycyclic group” refer to two or more rings(e.g., cycloalkyls, cycloalkenyls, cycloalkynyls, aryls and/orheterocyclyls) in which two or more carbons are common to two adjoiningrings, e.g., the rings are “fused rings”. Rings that are joined throughnon-adjacent atoms are termed “bridged” rings. Each of the rings of thepolycycle can be substituted with such substituents as described above,as for example, halogen, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl,hydroxyl, amino, nitro, sulfhydryl, imino, amido, phosphate,phosphonate, phosphinate, carbonyl, carboxyl, silyl, ether, alkylthio,sulfonyl, ketone, aldehyde, ester, a heterocyclyl, an aromatic orheteroaromatic moiety, —CF₃, —CN, or the like.

The phrase “protecting group” as used herein means temporarysubstituents which protect a potentially reactive functional group fromundesired chemical transformations. Examples of such protecting groupsinclude esters of carboxylic acids, silyl ethers of alcohols, andacetals and ketals of aldehydes and ketones, respectively. The field ofprotecting group chemistry has been reviewed (Greene, T. W.; Wuts, P. G.M. Protective Groups in Organic Synthesis, 2^(nd) ed.; Wiley: New York,1991).

As used herein, the term “substituted” is contemplated to include allpermissible substituents of organic compounds. In a broad aspect, thepermissible substituents include acyclic and cyclic, branched andunbranched, carbocyclic and heterocyclic, aromatic and nonaromaticsubstituents of organic compounds. Illustrative substituents include,for example, those described herein above. The permissible substituentscan be one or more and the same or different for appropriate organiccompounds. For purposes of this invention, the heteroatoms such asnitrogen may have hydrogen substituents and/or any permissiblesubstituents of organic compounds described herein which satisfy thevalences of the heteroatoms. This invention is not intended to belimited in any manner by the permissible substituents of organiccompounds.

It will be understood that “substitution” or “substituted with” includesthe implicit proviso that such substitution is in accordance withpermitted valence of the substituted atom and the substituent, and thatthe substitution results in a stable compound, e.g., which does notspontaneously undergo transformation such as by rearrangement,cyclization, elimination, etc.

The term “statistically significant” as used herein means that theobtained results are not likely to be due to chance fluctuations at thespecified level of probability. The two most commonly specified levelsof significance are 0.05 (p=0.05) and 0.01 (p=0.01). The level ofsignificance equal to 0.05 and 0.01 means that the probability of erroris 5 out of 100 and 1 out of 100, respectively.

The term “sulfamoyl” is art-recognized and includes a moiety that can berepresented by the general formula:

in which R₉ and R₁₀ are as defined above.

The term “sulfate” is art recognized and includes a moiety that can berepresented by the general formula:

in which R₄₁ is an electron pair or represents a metal or aminergiccounterion, hydrogen, alkyl, cycloalkyl, or aryl.

The term “sulfonamido” is art recognized and includes a moiety that canbe represented by the general formula:

in which R₉ and R′₁₁ are a s defined above.

The term “sulfonate” is art-recognized and includes a moiety that can berepresented by the general formula:

in which R₄₁ is an electron pair or represents a metal or aminergiccounterion, hydrogen, alkyl, cycloalkyl, or aryl.

The terms “sulfoxido” or “sulfinyl”, as used herein, refers to a moietythat can be represented by the general formula:

in which R₄₄ is selected from the group consisting of hydrogen, alkyl,alkenyl, alkynyl, cycloalkyl, heterocyclyl, aralkyl, or aryl.

The term “sulfonyl”, as used herein, refers to a moiety that can berepresented by the general formula:

in which R₄₄ is selected from the group consisting of hydrogen, alkyl,alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, or heteroaryl.

Analogous substitutions can be made to alkenyl and alkynyl groups toproduce, for example, aminoalkenyls, aminoalkynyls, amidoalkenyls,amidoalkynyls, iminoalkenyls, iminoalkynyls, thioalkenyls, thioalkynyls,carbonyl-substituted alkenyls or alkynyls.

As used herein, the definition of each expression, e.g., alkyl, m, n,etc., when it occurs more than once in any structure, is intended to beindependent of its definition elsewhere in the same structure.

Contemplated equivalents of the compounds described above includecompounds which otherwise correspond thereto, and which have the samegeneral properties thereof (e.g., the ability to effect long-termmemory), wherein one or more simple variations of substituents are madewhich do not adversely affect the efficacy of the compound. In general,the compounds of the present invention may be prepared by the methodsdescribed below, or by modifications thereof, using readily availablestarting materials, reagents and conventional synthesis procedures. Inthese reactions, it is also possible to make use of variants which arein themselves known, but are not mentioned here.

For purposes of this invention, the chemical elements are identified inaccordance with the Periodic Table of the Elements, CAS version,Handbook of Chemistry and Physics, 67th Ed., 1986-87, inside cover. Alsofor purposes of this invention, the term “hydrocarbon” is contemplatedto include all permissible compounds having at least one hydrogen andone carbon atom. In a broad aspect, the permissible hydrocarbons includeacyclic and cyclic, branched and unbranched, carbocyclic andheterocyclic, aromatic and nonaromatic organic compounds which can besubstituted or unsubstituted.

Exemplary Compounds of the Invention

In preferred embodiments of the invention, a compound useful in thecompositions and methods described herein has a structure of Formula I:

wherein, as valence and stability permit,

R₁, independently for each occurrence, represents H or substituted orunsubstituted lower alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl,heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl, e.g.,optionally substituted by one or more substitutents such as halogen,hydroxy, alkoxy, etc.;

R₂ represents H or lower alkyl, lower alkenyl, lower alkynyl, aralkyl,aryl, heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl, e.g.,optionally substituted by one or more substitutents such as halogen,hydroxy, alkoxy, etc.;

R₃ represents H or lower alkyl, lower alkenyl, lower alkynyl, aralkyl,aryl, heteroaralkyl, heteroaryl, cycloalkyl, or cycloalkylalkyl, e.g.,optionally substituted by one or more substitutents such as halogen,hydroxy, alkoxy, etc.;

R₄ is absent, or represents from 1 to 3 substituents on the ring towhich it is attached, e.g., selected from halogen, hydroxy, alkoxy,amino, alkylamino, sulfhydryl, alkylthio, cyano, nitro, ester, ketone,formyl, amido, acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonateester, amidino, sulfonyl, sulfoxido, sulfamoyl, sulfonamido, andphosphonate, etc.

In certain embodiments, at least one occurrence of R₁ representshydrogen. In certain embodiments, both occurrences of R₁ representhydrogen. In other embodiments, one occurrence of R₁ represents loweralkyl, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,t-butyl, etc.

In certain embodiments, R₂ represents hydrogen, while in otherembodiments, R₂ represents lower alkyl, such as methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl, t-butyl, etc.

In certain embodiments, R₃ represents hydrogen, while in otherembodiments, R₃ represents lower alkyl, such as methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl, t-butyl, etc., hydroxy, amino, orcarbonyl.

In certain embodiments, R₄ represents hydrogen, while in otherembodiments, R₄ represents from 1 to 3 substituents on the ring to whichit is attached selected from halogen, hydroxy, amino, sulfhydryl, cyano,nitro, and lower alkyl.

In certain embodiments, R₄ represents hydrogen and at least one of R₁,R₂, and R₃ represents hydrogen. In certain embodiments, R₄ is absent andat least two of R₁, R₂, and R₃ represent hydrogen. In certainembodiments, R₄ represents hydrogen and at least three of R₁, R₂, and R₃represent hydrogen. In certain embodiments, R₄ represents hydrogen andall four of R₁, R₂, and R₃ represent hydrogen.

As set out above, certain embodiments of compounds of Formula I maycontain a basic functional group, such as amino or alkylamino, and thus,can be utilized in a free base form or as pharmaceutically acceptablesalt forms derived from pharmaceutically acceptable organic andinorganic acids.

The pharmaceutically acceptable salts of the subject compoundsrepresented by Formula I include the conventional non-toxic salts of thecompounds, e.g., from non-toxic organic or inorganic acids. For example,such conventional non-toxic salts include those derived from inorganicacids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric,nitric, and the like; and the salts prepared from organic acids such asacetic, 2-acetoxybenzoic, ascorbic, benzene sulfonic, benzoic,chloroacetic, citric, ethane disulfonic, ethane sulfonic, formic,fumaric, gluconic, glutamic, glycolic, hydroxymaleic, isothionic,lactic, maleic, malic, methanesulfonic, oxalic, palmitic, phenylacetic,propionic, salicyclic, stearic, succinic, sulfanilic, tartaric,toluenesulfonic, and the like.

In particular, the sulfate saly of l-amphetamine represented by FormulaIV (C105) and the hydrochloride salt of l-methamphetamine represented byFormula V (SN522) are employed in the methods described herein.

In certain embodiments, such salts have a structure represented by thegeneral formula II:

wherein, as valence and stability permit,

R₁, R₂, R₃, and R₄ are defined as above;

L is a non-toxic organic or inorganic acid.

In certain embodiments, L is selected from the following inorganicacids: hydrochloric, hydrobromic, nitric, phosphoric, sulfamic, andsulfuric, or from the following organic acids: 2-acetoxybenzoic,ascorbic, benzene sulfonic, benzoic, chloroacetic, citric, ethanedisulfonic, ethane sulfonic, formic, fumaric, gluconic, glutamic,glycolic, hydroxymaleic, isothionic, lactic, maleic, malic,methanesulfonic, oxalic, palmitic, phenylacetic, propionic, salicyclic,stearic, succinic, sulfanilic, tartaric, and toluenesulfonic.

The compounds of the present invention further include metabolites ofthe subject amphetamine compounds, included but not limited to thefollowing: p-hydroxyamphetamine, benzyl methyl ketone,1-phenylpropan-2-ol, benzoic acid, glycine, hippuric acid,p-hydroxynorephedrine, and N-hydroxylamphetamine.

In certain embodiments, these metabolites have a structure representedby the general formula III:

wherein, as valence and stability permit,

R₁, independently for each occurrence, represents hydrogen orsubstituted or unsubstituted lower alkyl, lower alkenyl, lower alkynyl,aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl, orcycloalkylalkyl, e.g., optionally substituted by one or moresubstitutents such as halogen, hydroxy, alkoxy, etc.;

R₂ represents hydrogen or lower alkyl, lower alkenyl, lower alkynyl,aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl, orcycloalkylalkyl, e.g., optionally substituted by one or moresubstitutents such as halogen, hydroxy, alkoxy, etc.;

R₃ represents hydrogen or lower alkyl, lower alkenyl, lower alkynyl,aralkyl, aryl, heteroaralkyl, heteroaryl, cycloalkyl, orcycloalkylalkyl, e.g., optionally substituted by one or moresubstitutents such as halogen, hydroxy, alkoxy, etc.;

R₄ represents from 1 to 3 substituents on the ring to which it isattached, e.g., selected from hydrogen, halogen, hydroxy, alkoxy, amino,alkylamino, sulfhydryl, alkylthio, cyano, nitro, ester, ketone, formyl,amido, acylamino, acyloxy, lower alkyl, lower alkenyl, sulfonate ester,amidino, sulfonyl, sulfoxido, sulfamoyl, sulfonamido, and phosphonate,etc.;

R₅ independently for each occurrence, represents hydrogen or hydroxy.

In certain embodiments, the method includes administering, conjointlywith the pharmaceutical preparation, one or more of a neuronal growthfactor, a neuronal survival factor, and a neuronal trophic factor.Additionally or alternatively, a subject compound may be administered inconjunction with a cholinergic, adrenergic, noradrenergic, dopaminergic,glutaminergic or other modulators. Other agents directed at modulatingGABA, NMDA, cannabinoid, AMPA, kainate, phosphodiesterase (PDE), PKA,PKC, CREB or nootropic systems may be important to the improvement ofcognitive function and may be administered in conjunction with a subjectcompound.

An agent to be administered conjointly with a subject compound may beformulated together with a subject compound as a single pharmaceuticalpreparation, e.g., as a pill or other medicament including both agents,or may be administered as a separate pharmaceutical preparation.

In another aspect, the present invention provides pharmaceuticalpreparations comprising, as an active ingredient amphetamine or aderivative thereof. The subject amphetamine compound is formulated in anamount sufficient to improve LTP in an animal. The subject preparationsand methods can be treatments using amphetamine compounds effective forhuman and/or animal subjects. In addition to humans, other animalsubjects to which the invention is applicable extend to both domesticanimals and livestock, raised either as pets or for commercial purposes.Examples are dogs, cats, cattle, horses, sheep, hogs, and goats.

Still another aspect of the invention relates to the use of amphetaminecompounds for lessening the severity or prophylactically preventing theoccurrence of learning and/or memory defects in an animal, and thus,altering the learning ability and/or memory capacity of the animal. As aresult, the compounds of the present invention may be useful fortreating and/or preventing memory impairment, e.g., due to toxicantexposure, brain injury, brain aneurysm, age-associated memoryimpairment, mild cognitive impairment, epilepsy, Multiple Sclerosis,age-associated memory impairment, Mild Cognitive Impairment, mentalretardation in children, and dementia resulting from a disease, such asParkinson's disease, Alzheimer's disease, AIDS, head trauma,Huntington's disease, Pick's disease, Creutzfeldt-Jakob disease,Anterior Communicating Artery Syndrome, hypoxia, post cardiac surgery,Downs Syndrome and Stroke. In addition, the compounds of the inventionmay be useful in enhancing memory in normal individuals.

The invention also relates to the conjoint use of a amphetamine compoundwith agents that mimic or stimulate PKC and/or PKA pathways.

A. Synthesis of Amphetamine Compounds

As described in further detail below, it is contemplated that thesubject methods can be carried out using a stereomerically enrichedpreparation in a eutomer of amphetamine compound(s), particularlyR-(−)-amphetamine, or a variety of different derivatives thereof. Thesuitability of use of a particular amphetamine compound can be readilydetermined, for example, by such drug screening assays as describedherein.

The subject amphetamine compounds, and derivatives thereof, can beprepared readily by employing known synthetic methodology. As is wellknown in the art, these coupling reactions are carried out underrelatively mild conditions and tolerate a wide range of “spectator”functionality. Additional compounds may be synthesized and tested in acombinatorial fashion, to facilitate the identification of additionalamphetamine compounds which may be employed in the subject method.

Numerous methods for synthesizing amphetamine and for resolving theenantiomers of amphetamine have been described in the art, see forexample: U.S. Pat. No. 5,075,338 to Knoll et al.; U.S. Pat. No.2,828,343 to Tindall; U.S. Pat. No. 3,458,576 to Bryan; UK Patent No. GB2,122,617; U.S. Pat. No. 3,996,381 to Florvall et al.; Croce et al.,1996, Gazz. Chim. Ital. 126:107-109; Mastagli et. al., 1950, Bull. Soc.Chim. Fr. 1045-1047; Smith et al., 1988, J. Med. Chem. 31:1558-1566;Bobranskii et al., 1941, J. Applied Chem. (U.S.S.R.) 14:410-414;Magidson, 1941, J. Gen. Chem. (U.S.S.R.) 11:339-343. The contents ofthese publications are incorporated herein by reference.

In one embodiment, a subject amphetamine compound can be synthesizedaccording to the methods set forth in U.S. Pat. No. 5,075,338. Briefly,amphetamine compounds of the general formula:

can be prepared by reacting a ketone of the formula:

with an amine of the formula: R″NH₂ and reducing the ketimineintermediate formed without or after isolation. The reduction can becarried out by methods known per se, e.g., by catalytic hydrogenation(preferably in the presence of a palladium or Raney-nickel catalyst) orby using a complex metal hydride (e.g. sodium borohydride) or with theaid of a conventional reducing agent (e.g. sodium dithionite oramalgamated aluminum).

R-(−)-amphetamine and S-(+)-amphetamine may be obtained by opticalresolution of racemic mixtures of R- and S-enantiomers of amphetamine.Such a resolution can be accomplished by any conventional resolutionmethods well known to a person skilled in the art, such as thosedescribed in J. Jacques, A. Collet and S. Wilen, “Enantiomers, Racematesand Resolutions,” Wiley, N.Y. (1981). For example, the resolution may becarried out by preparative chromatography on a chiral column. Anotherexample of a suitable resolution method is the formation ofdiastereomeric salts with a chiral acid such as tartaric, malic,mandelic acid or N-acetyl derivatives of amino acids, such as N-acetylleucine, followed by recrystallization to isolate the diastereomericsalt of the desired R enantiomer.

In one embodiment, a subject R-(−)-amphetamine may be resolved accordingto the methods set forth in J. Med. Chem, 1988, 31:1558:1570. Briefly,racemic amphetamine is combined with a hot ethanol solution ofD-(−)-tartaric acid. The solution is allowed to cool to room temperatureand the white crystals are collected and recrystallized twice more fromethanol to give D-tartaric acid salt of R-(−)-amphetamine. To recoverR-(−)-amphetamine, the D-tartaric acid salt of R-(−)-amphetamine istreated with sodium hydroxide in water and extracted with diethyl ether.

The compounds of the present invention may also be provided in the formof prodrugs, e.g., to protect a drug from being altered while passingthrough a hostile environment, such as the digestive tract. Prodrugs canbe prepared by forming covalent linkages between the drug and amodifier. See, for example, Balant at al., Eur. J. Drug Metab.Pharmacokinetics, 1990, 15(2), 143-153. The linkage is usually designedto be broken under defined circumstances, e.g., pH changes or exposureto specific enzymes. The covalent linkage of the drug to a modifieressentially creates a new molecule with new properties such as analtered log P value and/or as well as a new spatial configuration. Thenew molecule can have different solubility properties and be lesssusceptible to enzymatic digestion. For general references on prodrugdesign and preparation, see: Bundraard, Design of Prodrugs, ElsevierScience Pub. Co., N.Y. (1985), and Prodrugs as Novel Drug DeliverySystems Symposium, 168.sup.th Annual Meeting, American Chemical Society,Atlantic City, N.J., Eds. T. Higuchi and V. Stella, ACS Symposium Series14, 1975, which are herein incorporated by reference.

Prodrugs of amine-containing compounds are well known in the art andhave been prepared, e.g., by reacting the amine moiety of a drug with acarboxylic acid, acid chloride, chloroformate, or sulfonyl chloridemodifiers, and the like, resulting in the formation of amides,sulfonamides, carboxyamides, carbamates, Schiff bases and similarcompounds. See, for example, Abuchowski et al., J. Biol. Chem. 1977,252, 3578-358; Senter et al., J. Org. Chem., 1990, 55, 2975-2978;Amsberry et al., J. Org. Chem., 1990, 55, 5867-5877; Klotz, Clin.Pharmacokinetics, 1985, 10, 285-302, which are herein incorporated byreference. Similar and other protocols may be followed for the formationof prodrugs of the compounds of the present invention.

The compounds of the present invention, particularly libraries ofamphetamine analogs having various representative classes ofsubstituents, are amenable to combinatorial chemistry and other parallelsynthesis schemes (see, for example, PCT WO 94/08051). The result isthat large libraries of related compounds, e.g., a variegated library ofcompounds represented above, can be screened rapidly in high throughputassays in order to identify potential amphetamine analogs, as well as torefine the specificity, toxicity, and/or cytotoxic-kinetic profile of alead compound.

Simply for illustration, a combinatorial library for the purposes of thepresent invention is a mixture of chemically related compounds which maybe screened together for a desired property. The preparation of manyrelated compounds in a single reaction greatly reduces and simplifiesthe number of screening processes which need to be carried out.Screening for the appropriate physical properties can be done byconventional methods.

Diversity in the library can be created at a variety of differentlevels. For instance, the substrate aryl groups used in thecombinatorial reactions can be diverse in terms of the core aryl moiety,e.g., a variegation in terms of the ring structure, and/or can be variedwith respect to the other substituents.

A variety of techniques are available in the art for generatingcombinatorial libraries of small organic molecules such as the subjectamphetamine compounds. See, for example, Blondelle et al. (1995) TrendsAnal. Chem. 14:83; the Affymax U.S. Pat. Nos. 5,359,115 and 5,362,899:the Ellman U.S. Pat. No. 5,288,514: the Still et al. PCT publication WO94/08051; the ArQule U.S. Pat. Nos. 5,736,412 and 5,712,171; Chen et al.(1994) JACS 116:2661: Kerr et al. (1993) JACS 115:252; PCT publicationsWO92/10092, WO93/09668 and WO91/07087; and the Lerner et al. PCTpublication WO93/20242). Accordingly, a variety of libraries on theorder of about 100 to 1,000,000 or more diversomers of the subjectamphetamine compounds can be synthesized and screened for particularactivity or property.

In an exemplary embodiment, a library of candidate amphetamine compounddiversomers can be synthesized utilizing a scheme adapted to thetechniques described in the Still et al. PCT publication WO 94/08051,e.g., being linked to a polymer bead by a hydrolyzable or photolyzablegroup, optionally located at one of the positions of the candidateregulators or a substituent of a synthetic intermediate. According tothe Still et al. technique, the library is synthesized on a set ofbeads, each bead including a set of tags identifying the particulardiversomer on that bead. The bead library can then be “plated” withcells for which an amphetamine compound is sought. The diversomers canbe released from the bead, e.g., by hydrolysis.

Many variations on the above and related pathways permit the synthesisof widely diverse libraries of compounds which may be tested asamphetamine compounds.

B. Generation of Animal Models to Test Agents

Applicants have previously described an animal model for studyingfornix-mediated memory consolidation. See, for example, Taubenfield etal., Supra. The fornix-lesioned animals can be used for drug screening,e.g., to identify dosages of the subject compositions which enhancememory consolidation. The lesioned mammal can have a lesion of theformix or a related brain structure that disrupts memory consolidation(e.g., perirhinal cortex, amygdala, medial septal nucleus, locuscoeruleus, hippocampus, mammallary bodies). Lesions in the mammal can beproduced by mechanical or chemical disruption. For example, the fornixlesion can be caused by surgical ablation, electrolytic, neurotoxic andother chemical ablation techniques, or reversible inactivation such asby injection of an anesthetic, e.g., tetrodotoxin or lidocaine, totemporarily arrest activity in the formix.

To further illustrate, fimbrio-formix (rodents) and formix (primates)lesions can be created by stereotactic ablation. In particular, neuronsof the formix structure are axotomized, e.g., by transection oraspiration (suction) ablation. A complete transection of the formixdisrupts adrenergic, cholinergic and GABAergic function and electricalactivity, and induces morphological reorganization in the hippocampalformation. In general, the formix transection utilized in the subjectmethod will not disconnect the parahippocampal region from theneocortex. In those embodiments, the formix transection will not disruptfunctions that can be carried out by the parahippocampal regionindependent of processing by the hippocampal formation, and hence wouldnot be expected to produce the full-blown amnesia seen following morecomplete hippocampal system damage.

In one embodiment, the animal can be a rat. Briefly, the animals areanesthetized, e.g., with intraperitoneal injections of aketamine-xylazine mixture and positioned in a Kopf® stereotaxicinstrument. A sagittal incision is made in the scalp and a craniotomy isperformed extending 2.0 mm posterior and 3.0 mm lateral from Bregma. Anaspirative device, e.g., with a 20 gauge tip, is mounted to astereotaxic frame (Kopf® Instruments) and fimbria-formix is aspirated byplacing the suction tip at the correct sterotaxic location in theanimal's brain. Unilateral aspirative lesions are made by suctionthrough the cingulate cortex, completely transecting the fimbria formixunilaterally, and (optionally) removing the dorsal tip of thehippocampus as well as the overlying cingulate cortex to inflict apartial denervation on the hippocampus target. See also, Gage et al.,(1983) Brain Res. 268:27 and Gage et al. (1986) Neuroscience 19:241.

In another exemplary embodiment, the animal can be a monkey. The animalcan be anesthetized, e.g., with isoflurane (1.5-2.0%). Followingpretreatment with mannitol (0.25 g/kg, iv), unilateral transections ofthe left formix can be performed, such as described by Kordower et al.(1990) J. Comp. Neurol., 298:443. Briefly, a surgical drill is used tocreate a parasagittal bone flap which exposes the frontal superiorsagittal sinus. The dura is retracted and a self-retaining retractor isused to expose the interhemispheric fissure. The corpus callosum islongitudinally incised. At the level of the foramen of Monro, the formixis easily visualized as a discrete 2-3 mm wide white fiber bundle. Theformix can be initially transected using a ball dissector. The cut endsof the formix can then be suctioned to ensure completeness of thelesion.

In still other illustrative embodiments, the formix lesion can becreated by excitotoxicity, or by other chemical means, inhibiting orablating formix neurons, or the cells of the hippocampus which areinnervated by formix neurons. In certain preferred embodiments, theformix lesion is generated by selective disruption of particularneuronal types, such as formix cholinergic and adrenergic neurons.

For instance, the afferant formix signals to the hippocampus due tocholinergic neurons can be ablated by atropine blockade. Another meansfor ablation of the cholinergic neurons is the use of 192IgG-saporin(192IgG-sap), e.g., intraventricularly injection into the formix andhippocampus. The agents such as 6-OHDA and ibotenic acid can be used toselectively destroy formix dopamine neurons as part of the ablativeregimen.

In one embodiment, the animal is a non-human mammal, such as a dog, cat,horse, cow, pig, sheep, goat, chicken, monkey, ape, rat, rabbit, etc. Inanother embodiment, the animal is a non-human primate. In still anotherembodiment, the subject is a human.

There are a variety of tests for cognitive function, especially learningand memory testing, which can be carried our using the lesioned andnormal animals. Learning and/or memory tests include, for example,Inhibitory Avoidance Test (also referred to herein as “Passive AvoidanceTest”), contextual fear conditioning, visual delay non-match to sample,spatial delay non-match to sample, visual discrimination, Barnescircular maze, Morris water maze, radial arm maze tests, RayAuditory-Visual Learning Test, the Wechsler Logical Memory Test, and theProvidence Recognition Memory Test.

An exemplary Inhibitory Avoidance Test utilizes an apparatus thatconsists of a lit chamber that can be separated from a dark chamber by asliding door. At training, the animal is placed in the lit chamber forsome period of time, and the door is opened. The animal moves to thedark chamber after a short delay—the step-through latency—which isrecorded. Upon entry into the dark chamber, the door is shut closed anda foot shock is delivered. Retention of the experience is determinedafter various time intervals, e.g., 24 or 48 hours, by repeating thetest and recording the latency. The protocol is one of many variants ofthe passive avoidance procedures (for review, see Rush (1988) Behav.Neural. Biol. 50:255).

An exemplary maze testing embodiment is the water maze working memorytest. In general, the method utilizes an apparatus which consists of acircular water tank. The water in the tank is made cloudy by theaddition of milk powder. A clear plexiglass platform, supported by amovable stand rest on the bottom of the tank, is submerged just belowthe water surface. Normally, a swimming rat cannot perceive the locationof the platform but it may recall it from a previous experience andtraining, unless it suffers from some memory impairment. The time takento locate the platform is measured and referred to as the latency.During the experiment, all orientational cues such as ceiling lights,etc., remain unchanged. Longer latencies are generally observed withrats with some impairment to their memory.

Another memory test includes the eyeblink conditioning test, whichinvolves the administration of white noise or steady tone that precedesa mild air puff which stimulates the subject's eyeblink.

Still another memory test which can be used is fear conditioning, e.g.,either “cued” and “contextual” fear conditioning. In one embodiment, afreeze monitor administers a sequence of stimuli (sounds, shock) andthen records a series of latencies measuring the recovery from shockinduced freezing of the animal.

Another memory test for the lesioned animals is a holeboard test, whichutilizes a rotating holeboard apparatus containing (four) open holesarranged in a 4-corner configuration in the floor of the test enclosure.A mouse is trained to poke its head into a hole and retrieve a foodreward from a “baited” hole which contains a reward on every trial.There is a food reward (e.g., a Fruit Loop) in every exposed hole whichis made inaccessible by being placed under a screen. The screen allowsthe odor of the reward to emanate from the hole, but does not allowaccess to the reinforcer. When an individual hole is baited, a reward isplaced on top of the screen, where it is accessible. The entireapparatus rests on a turntable so that it may be rotated easily toeliminate reliance on proximal (e.g., olfactory) cues. A start tube isplaced in the center of the apparatus. The subject is released from thetube and allowed to explore for the baited (“correct”) hole.

As set out above, one use for the formix-lesioned animals is for testingamphetamine compounds for ability to modulate memory consolidation, aswell as for side effects and toxicity. In general, the subject methodutilizes an animal which has been manipulated to create at least partialdisruption of formix-mediated signalling to the hippocampus, thedisruption affecting memory consolidation and learned behavior in theanimal. The animal is conditioned with a learning or memory regimenwhich results in learned behavior in the mammal in the absence of theformix lesion. Amphetamine compounds are administered to the animal inorder to assess their effects on memory consolidation. An increase inlearned behavior, relative to the absence of the test agents, indicatesthat the administered combination enhances memory consolidation.

Another memory test especially developed for use in pharmaceuticalstudies is the Providence Recognition Memory Test. This test consists ofone pictorial and one verbal assessment of long-term declarative memory.In each of the two modes, the patient views stimuli on a computer screenand is later asked to recognize those stimuli in a two-alternativeforced-choice format. The pictorial assessment mode consists of twoparts: a study phase and a recognition phase. In the study phase,patients view a series of 120 pictures, for 3 seconds each. They aretold to look at the pictures and remember them, so that they canrecognize them later. In the recognition phase, patients view picturestwo at a time and are asked to indicate by button press which of the twopictures they saw in a study phase. Recognition memory testing occurs atten minutes, one hour, and 24 hours after the end of the study phase.The verbal assessment mode consists of two parts: a study phase and arecognition phase. In the study phase, patients view a series of 60sentences one at a time. They are asked to read the sentences aloud andremember them, so that they can recognize them later. Each sentenceremains on the computer screen until the patient has finished reading italoud. If patients read words incorrectly, the examiner supplies thecorrect word or words. In the recognition phase, patients view sentencestwo at a time and are asked to indicate by button press which of the twosentences they saw in the study phase. Recognition memory testing occursat ten minutes, one hour, and 24 hours after the end of the study phase.

In the methods of the present invention, retention of the learnedbehavior can be determined, for example, after at least about 12-24hours, 14-22 hours, 16-20 hours and or 18-19 hours after completion ofthe learning phase to determine whether the agents promote memoryconsolidation. In a particular embodiment, retention of the learnedbehavior can be determined 24 hours after completion of the learningphase.

In addition to models for studying memory consolidation, models toassess side effects of amphetamine compounds on behavior have beenutilized including locomotor activity models. An exemplary locomotoractivity test utilizes an apparatus that consists of photocell activitycages with a grid of photocell beams placed around the cage. The animalsare placed in individual activity cages some period of time prior toadministration of agents. Locomotor activity is measured by the numberof interruptions of the photoelectric beam during a given period oftime.

As used herein, a “control mammal” can be an untreated lesion mammal(i.e., a lesion animal receiving no agents or not the same combinationsto be assessed), a trained control mammal (i.e., a mammal that undergoestraining to demonstrate a learned behavior without any lesion) and/or anuntrained control mammal (i.e., a mammal with or without a lesion, thatreceives no training to demonstrate a learned behavior).

C. Pharmaceutical Preparations of Amphetamine Compounds

In another aspect, the present invention provides pharmaceuticalpreparations comprising the subject amphetamine compounds. Theamphetamine compounds for use in the subject method may be convenientlyformulated for administration with a biologically acceptable,non-pyrogenic, and/or sterile medium, such as water, buffered saline,polyol (for example, glycerol, propylene glycol, liquid polyethyleneglycol and the like) or suitable mixtures thereof. The optimumconcentration of the active ingredient(s) in the chosen medium can bedetermined empirically, according to procedures well known to behavioralscientists. As used herein, “biologically acceptable medium” includesany and all solvents, dispersion media, and the like which may beappropriate for the desired route of administration of thepharmaceutical preparation. The use of such media for pharmaceuticallyactive substances is known in the art. Except insofar as anyconventional media or agent is incompatible with the activity of theamphetamine compounds, its use in the pharmaceutical preparation of theinvention is contemplated. Suitable vehicles and their formulationinclusive of other proteins are described, for example, in the bookRemington's Pharmaceutical Sciences (Remington's PharmaceuticalSciences. Mack Publishing Company, Easton, Pa., USA 1985). Thesevehicles include injectable “deposit formulations”.

Pharmaceutical formulations of the present invention can also includeveterinary compositions, e.g., pharmaceutical preparations of theamphetamine compounds suitable for veterinary uses, e.g., for thetreatment of livestock or domestic animals, e.g., dogs.

Methods of introduction may also be provided by rechargeable orbiodegradable devices. Various slow release polymeric devices have beendeveloped and tested in vivo in recent years for the controlled deliveryof drugs. A variety of biocompatible polymers (including hydrogels),including both biodegradable and non-degradable polymers, can be used toform an implant for the sustained release of a amphetamine compound at aparticular target site. In accordance with the practice of thisinvention, it has been found that a dosage form and a method can beprovided that administers a amphetamine compound in a program thatsubstantially lessens or completely compensates for tolerance in apatient. Tolerance, as defined in Pharmacology in Medicine, by Brill, p.227 (1965) McGraw-Hill, is characterized as a decrease in effectfollowed by administering a drug. When tolerance develops following asingle dose or a few doses over a very short time, it is referred to asacute tolerance. When the drug is administered over a more protractedperiod of time to show a demonstrable degree of tolerance, it isreferred to as chronic tolerance. The medical literature, as exemplifiedin, The Pharmacological Bases of Therapeutics, by Goodman and Gilman,8th Ed., p. 72 (1990) Pergamon Press, reported tolerance may be acquiredto the effects of many drugs and this literature classifies tolerance asacute or chronic based on when it is acquired. That is, acute tolerancedevelops during a dosing phase of one dose or on one day, and chronictolerance is acquired due to chronic administration typically weeks,months, and years.

In certain embodiments, particularly where the selected amphetaminecompound is one which may produce tolerance, e.g., acute tolerance, inthe patient, it may desirable to formulate the compound for variabledosing, and preferably for use in a dose-escalation regimen. Inpreferred embodiments, the subject amphetamine compounds are formulatedto deliver a sustained and increasing dose, e.g., over at least 4 hours,and more preferably over at least 8 or even 16 hours.

In certain embodiments, representative dosage forms include hydrogelmatrix containing a plurality of tiny pills. The hydrogel matrixcomprises a hydrophilic polymer, such as selected from the groupconsisting of a polysaccharide, agar, agarose, natural gum, alkalialginate including sodium alginate, carrageenan, fucoidan, furcellaran,laminaran, hypnea, gum arabic, gum ghatti, gum karaya, gum tragacanth,locust bean gum, pectin, amylopectin, gelatin and a hydrophilic colloid.The hydrogel matrix comprises a plurality of tiny pills (such as 4 to50), each tiny pill comprising an increasing dose population of from 100ng ascending in dose such as 0.5 mg, 1 mg, 1.2 mg, 1.4 mg, 1.6 mg, 1.8mg, etc. The tiny pills comprise a release rate controlling wall of 0.0mm to 10 mm thickness to provide for the timed ascending release ofdrug. Representative of wall-forming materials include a triglycerylester selected from the group consisting of glyceryl tristearate,glyceryl monostearate, glyceryl dipalmitate, glyceryl laureate, glyceryldidecenoate and glyceryl tridecenoate. Other wall forming materialscomprise polyvinyl acetate phthalate, methylcellulose phthalate, andmicroporous vinyl olefins. Procedures for manufacturing tiny pills aredisclosed in U.S. Pat. Nos. 4,434,153; 4,721,613; 4,853,229; 2,996,431;3,139,383 and 4,752,470, which are incorporated by reference herein.

In certain embodiments, the drug releasing beads are characterized by adissolution profile wherein 0 to 20% of the beads undergo dissolutionand release the drug in 0 to 2 hours, 20 to 40% undergo dissolution andrelease the drug in 2 to 4 hours, 40 to 60% exhibit dissolution andrelease in 4 to 6 hours, 60 to 80% in 6 to 8 hours, and 80 to 100% in 8to 10 hours. The drug releasing beads can include a central compositionor core comprising a drug and pharmaceutically acceptable compositionforming ingredients including a lubricant, antioxidant, and buffer. Thebeads comprise increasing doses of drug, for example, 1 mg, 2 mg, 5 mg,and so forth to a high dose, in certain preferred embodiments, of 15 to100 mg. The beads are coated with a release rate controlling polymerthat can be selected utilizing the dissolution profile disclosed above.The manufacture of the beads can be adapted from, for example, Liu etal. (1994) Inter. J. of Pharm., 112:105-116; Liu et al. (1994) Inter. J.of Pharm., 112:117-124; Pharm. Sci., by Remington, 14th Ed. pp.1626-1628 (1970); Fincher et al. (1968) J. Pharm. Sci., 57:1825-1835;and U.S. Pat. No. 4,083,949.

Another exemplary dosage form provided by the invention comprises aconcentration gradient of amphetamine compound from 1 mg to 15-600 mgcoated from the former low dose to the latter high dose on a polymersubstrate. The polymer can be erodible or a nonerodible polymer. Thecoated substrate is rolled about itself from the latter high dose at thecenter of the dosage form, to the former low dose at the exposed outerend of the substrate. The coated substrate is rolled from the high doseto the low dose to provide for the release of from low to high dose asthe substrate unrolls or erodes. For example, 1 mg to 600 mg ofamphetamine is coated onto an erodible polymer such as an polypeptide,collagen, gelatin, or polyvinyl alcohol, and the substrate rolledconcentrically from the high dose rolled over and inward to adapt acenter position, and then outward towards the low dose to form an outerposition. In operation, the dosage form erodes dispensing an ascendingdose of amphetamine that is released over time.

Another dosage form provided by the invention comprises a multiplicityof layers, wherein each layer is characterized by an increasing dose ofdrug. The phrase “multiplicity of layers” denotes 2 to 6 layers incontacting lamination. The multiplicity of layers are positionedconsecutively, that is, one layer after another in order, with a firstexposed layer, the sixth layer in contact with the fifth layer and itsexposed surface coated with a drug impermeable polymer. The sixth layeris coated with a drug impermeable polymer to insure release of theamphetamine compound from the first layer to the sixth layer. The firstlayer comprises, for example, 1 to 50 mg of drug and each successivelayer comprises an additional 1 to 50 mg of drug. The biodegradablepolymers undergo chemical decomposition to form soluble monomers orsoluble polymer units. The biodegradation of polymers usually involveschemically or enzymatically catalyzed hydrolysis. Representative ofbiodegradable polymers acceptable for an increase drug loading in eachlayer of from 5 to 50 wt % over the first and successive layers whereinthe first layer comprises 100 ng. Representative biodegradable polymerscomprise a member selected from the group consisting of biodegradablepoly(amides), poly(amino acids), poly(esters), poly(lactic acid),poly(glycolic acid), poly(orthoesters), poly(anhydrides), biodegradablepoly(dehydropyrans), and poly(dioxinones). The polymers are known to theart in Controlled Release of Drugs, by Rosoff, Ch. 2, pp. 53-95 (1989);and in U.S. Pat. Nos. 3,811,444; 3,962,414; 4,066,747; 4,070,347;4,079,038; and 4,093,709.

In still other embodiments, the invention employs a dosage formcomprising a polymer that releases a drug by diffusion, flux throughpores, or by rupture of a polymer matrix. The drug delivery polymericsystem comprises a concentration gradient, wherein the gradient is anascent in concentration from a beginning or initial concentration to afinal, or higher concentration. The dosage form comprises an exposedsurface at the beginning dose and a distant nonexposed surface at thefinal dose. The nonexposed surface is coated with a pharmaceuticallyacceptable material impermeable to the passage of drug. The dosage formstructure provides for a flux increase delivery of drug ascending fromthe beginning to the final delivered dose.

FIG. 17 illustrates such an embodiment, where the amphetamine compoundis contained within a nonabsorbable shell that releases the drug at acontrolled rate.

The dosage form matrix can be made by procedures known to the polymerart. In one manufacture, 3 to 5 or more casting compositions areindependently prepared wherein each casting composition comprises anincreasing dose of drug with each composition overlayered from a low tothe high dose. This provides a series of layers that come together toprovide a unit polymer matrix with a concentration gradient. In anothermanufacture, the higher does is cast first followed by laminating withlayers of decreasing dose to provide a polymer matrix with a drugconcentration gradient. An example of providing a dosage form comprisesblending a pharmaceutically acceptable carrier, like polyethyleneglycol, with a known dose of a amphetamine compound and adding it to asilastic medical grade elastomer with a cross-linking agent, likestannous octanoate, followed by casting in a mold. The step is repeatedfor each successive layer. The system is allowed to set, for 1 hour, toprovide the dosage form. Representative polymers for manufacturing thedosage form comprise a member selected from the group consisting ofolefin and vinyl polymers, condensation polymers, carbohydrate polymers,and silicon polymers as represented by poly(ethylene), poly(propylene),poly(vinyl acetate), poly(methyl acrylate), poly(isobutyl methacrylate),poly(alginate), poly(amide), and poly(silicone). The polymers andmanufacturing procedures are known in Polymers, by Coleman et al., Vol.31, pp. 1187-1230 (1990); Drug Carrier Systems, by Roerdink et al., Vol.9, pp. 57-109 (1989); Adv. Drug Delivery Rev., by Leong et al., Vol. 1,pp. 199-233 (1987); Handbook of Common Polymers, Compiled by Roff etal., (1971) published by CRC Press; and U.S. Pat. No. 3,992,518.

In still other embodiments, the subject formulations can be a mixture ofdifferent prodrug forms of one or more different amphetamine compounds,each prodrug form having a different hydrolysis rate, and thereforeactivation rate, to provide an increasing serum concentration of theactive amphetamine compounds.

In other embodiments, the subject formulations can be a mixturedifferent amphetamine compounds, each compound having a different rateof adsorption (such as across the gut or epithelia) and/or serumhalf-life.

The dose-escalation regimen of the present invention can be used tocompensate for the loss of a therapeutic effect of a amphetaminecompound, if any, by providing a method of delivery that continuallycompensates for the development of acute tolerance, by considering theclinical effect (E) of a drug at time (t) as a function of the drugconcentration (C) according to Equation 1:Effect=f(t, C)

In addition, the rate of drug delivered (A), in mg per hour is inverselyproportional to the concentration times the clearance of the drug. Asthe effect varies with time and the functionality is expressed, thenaccording to this invention (A) can be governed to ensure thetherapeutic effect is maintained at a clinical value. If the effect froma drug is found clinically to decrease with time, this decline could belinear as expressed by Equation 2:Effect_((t))=Effect_((ini)) −k _(effect) *twherein, Effect_((ini)) is the clinical effect observed initially at thestart of drug administration and Effect(t) is the effect observed attime (t) hours, keffect is a proportionality constant ascertained bymeasuring the clinical effect (E1) at time (t1) hours and (E2) at time(t2) hours while maintaining a constant plasma concentration followed bydividing (E1) minus (E2) by (t1) minus (t2). In order to maintain aconstant effect, (A) must be adjusted with the same functionalityaccording to Equation 3:A _((t)) =A _((ini)) +k _(effect) *twherein A_((ini)) is the initial drug input in mg per hour at the startof the therapy and A_((t)) is the drug input at time (t) hours, andkeffect is the proportionality constant presented above. If thetherapeutic effect is found to decline exponentially with time, thisrelationship is expressed by Equation 4:Effect_((t))=Effect_((ini))*exp^((−keffect*t))wherein Effect_((ini)) and Effect_((t)) are as defined before, keffect(or keffect) is a rate constant (h−1), a unit of reciprocal hours,ascertained by measuring the clinical effect (E1) at time (t1) hours and(E2) at time (t2) hours while maintaining a constant plasmaconcentration followed by dividing natural log of (E1) minus natural logof (E2) by (t1) minus (t2). To maintain a constant effect, (A) must beadjusted according to Equation 5:A _((t)) =A _((ini))*exp^((keffect*t))wherein A_((ini)) and A_((t)) are as defined before, keffect is the rateconstant (h−1) presented above. The equations are presented in Holfordet al. (1982) Pharmac. Ther., 16:143-166.

The preparations of the present invention may be given orally,parenterally, topically, or rectally. They are of course given by formssuitable for each administration route. For example, they areadministered in tablets or capsule form, by injection, infusion,inhalation, rectal suppository, or controlled release patch. Oral andcontrolled release patch administrations are preferred.

In certain preferred embodiments, the subject therapeutic is deliveredby way of a transdermal patch. A patch is generally a flat hollow devicewith a permeable membrane on one side and also some form of adhesive tomaintain the patch in place on the patient's skin, with the membrane incontact with the skin so that the medication can permeate out of thepatch reservoir and into and through the skin. The outer side the patchis formed of an impermeable layer of material, and the membrane side andthe outer side are joined around the perimeter of the patch, forming areservoir for the medication and carrier between the two layers.

Patch technology is based on the ability to hold an active ingredient inconstant contact with the epidermis. Over substantial periods of time,drug molecules, held in such a state, will eventually find their wayinto the bloodstream. Thus, patch technology relies on the ability ofthe human body to pick up drug molecules through the skin. Transdermaldrug delivery using patch technology has recently been applied fordelivery of nicotine, in an effort to assist smokers in quitting, thedelivery of nitroglycerine to angina sufferers, the delivery ofreplacement hormones in post menopausal women, etc. These conventionaldrug delivery systems comprise a patch with an active ingredient such asa drug incorporated therein, the patch also including an adhesive forattachment to the skin so as to place the active ingredient in closeproximity to the skin. Exemplary patch technologies are available fromCiba-Geigy Corporation and Alza Corporation. Such transdermal deliverydevices can be readily adapted for use with the subject amphetaminecompounds.

The flux of the subject amphetamines across the skin can be modulated bychanging either (a) the resistance (the diffusion coefficient), or (b)the driving force (the solubility of the drug in the stratum corneum andconsequently the gradient for diffusion). Various methods can be used toincrease skin permeation by the subject amphetamines, includingpenetration enhancers, use of pro-drug versions, superfluous vehicles,iontophoresis, phonophoresis and thermophoresis. Many enhancercompositions have been developed to change one or both of these factors.See, for example, U.S. Pat. Nos. 4,006,218; 3,551,154; and 3,472,931,for example, respectively describe the use of dimethylsulfoxide (DMSO),dimethyl formamide (DMF), and N,N-dimethylacetamide (DMA) for enhancingthe absorption of topically applied drugs through the stratum corneum.Combinations of enhancers consisting of diethylene glycol monoethyl ormonomethyl ether with propylene glycol monolaurate and methyl laurateare disclosed in U.S. Pat. No. 4,973,468. A dual enhancer consisting ofglycerol monolaurate and ethanol for the transdermal delivery of drugsis shown in U.S. Pat. No. 4,820,720. U.S. Pat. No. 5,006,342 listsnumerous enhancers for transdermal drug administration consisting offatty acid esters or fatty alcohol ethers of C2 to C4 alkanediols, whereeach fatty acid/alcohol portion of the ester/ether is of about 8 to 22carbon atoms. U.S. Pat. No. 4,863,970 shows penetration-enhancingcompositions for topical application comprising an active permeantcontained in a penetration-enhancing vehicle containing specifiedamounts of one or more cell-envelope disordering compounds such as oleicacid, oleyl alcohol, and glycerol esters of oleic acid; a C2 or C3alkanol; and an inert diluent such as water. Other examples are includedin the teachings of U.S. Pat. No. 4,933,184 which discloses the use ofmenthol as a penetration enhancer; U.S. Pat. No. 229,130 discloses theuse of vegetable oil (soybean and/or coconut oil) as a penetrationenhancer; and U.S. Pat. No. 4,440,777 discloses the use of eucalyptol asa penetration enhancer.

The phrases “parenteral administration” and “administered parenterally”as used herein means modes of administration other than enteral andtopical administration, usually by injection, and includes, withoutlimitation, intravenous, intramuscular, intraarterial, intrathecal,intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal,transtracheal, subcutaneous, subcuticular, intraarticular, subcapsular,subarachnoid, intraspinal and intrastemal injection and infusion.

The phrases “systemic administration,” “administered systemically,”“peripheral administration” and “administered peripherally” as usedherein mean the administration of a compound, drug or other materialother than directly into the central nervous system, such that it entersthe patient's system and, thus, is subject to metabolism and other likeprocesses, for example, subcutaneous administration.

These compounds may be administered to humans and other animals fortherapy by any suitable route of administration, including orally,nasally, as by, for example, a spray, rectally, intravaginally,parenterally, intracistemally and topically, as by powders, ointments ordrops, including buccally and sublingually.

Regardless of the route of administration selected, the compounds of thepresent invention, which may be used in a suitable hydrated form, and/orthe pharmaceutical compositions of the present invention, are formulatedinto pharmaceutically acceptable dosage forms such as described below orby other conventional methods known to those of skill in the art.

Actual dosage levels of the active ingredients in the pharmaceuticalcompositions of this invention may be varied so as to obtain an amountof the active ingredient which is effective to achieve the desiredtherapeutic response for a particular patient, composition, and mode ofadministration, without being toxic to the patient.

The selected dosage level will depend upon a variety of factorsincluding the activity of the particular compound of the presentinvention employed, or the ester, salt or amide thereof, the route ofadministration, the time of administration, the rate of excretion of theparticular compound being employed, the duration of the treatment, otherdrugs, compounds and/or materials used in combination with theparticular amphetamine compounds employed, the age, sex, weight,condition, general health and prior medical history of the patient beingtreated, and like factors well known in the medical arts.

A physician or veterinarian having ordinary skill in the art can readilydetermine and prescribe the effective amount of the pharmaceuticalcomposition required. For example, the physician or veterinarian couldstart doses of the compounds of the invention employed in thepharmaceutical composition at levels lower than that required in orderto achieve the desired therapeutic effect and gradually increase thedosage until the desired effect is achieved.

In general, a suitable daily dose of a compound of the invention will bethat amount of the compound which is the lowest dose effective toproduce a therapeutic effect. Such an effective dose will generallydepend upon the factors described above. Generally, intravenous,intracerebroventricular and subcutaneous doses of the compounds of thisinvention for a patient will range from about 0.0001 mg to about 100 mgper kilogram (kg) of body weight per day; about 0.0001 mg/kg to about500 mg/kg; or 0.0001 mg/kg to about 1000 mg/kg.

If desired, the effective daily dose of the active compound may beadministered as two, three, four, five, six or more sub-dosesadministered separately at appropriate intervals throughout the day,optionally, in unit dosage forms.

The term “treatment” is intended to encompass also prophylaxis, therapyand cure.

The patient receiving this treatment is any animal in need, includingprimates, in particular humans, and other mammals such as equines,cattle, swine and sheep; and poultry and pets in general.

The compound of the invention can be administered as such or inadmixtures with pharmaceutically acceptable carriers and can also beadministered in conjunction with other psychoactive drugs such asstimulants, antidepressants, modulators of neurotransmittors andanticonvulsants. Conjunctive therapy thus includes sequential,simultaneous and separate administration of the active compound in a waythat the therapeutic effects of the first administered one is notentirely disappeared when the subsequent is administered.

While it is possible for a compound of the present invention to beadministered alone, it is preferable to administer the compound as apharmaceutical formulation (composition). The amphetamine compoundsaccording to the invention may be formulated for administration in anyconvenient way for use in human or veterinary medicine.

Thus, another aspect of the present invention provides pharmaceuticallyacceptable compositions comprising a therapeutically effective amount ofone or more of the compounds described above, formulated together withone or more pharmaceutically acceptable carriers (additives) and/ordiluents. As described in detail below, the pharmaceutical compositionsof the present invention may be specially formulated for administrationin solid or liquid form, including those adapted for the following: (1)oral administration, for example, drenches (aqueous or non-aqueoussolutions or suspensions), tablets, boluses, powders, granules, pastesfor application to the tongue; (2) parenteral administration, forexample, by subcutaneous, intramuscular or intravenous injection as, forexample, a sterile solution or suspension; (3) topical application, forexample, as a cream, ointment or spray applied to the skin; or (4)intravaginally or intrarectally, for example, as a pessary, cream orfoam. However, in certain embodiments the subject compounds may besimply dissolved or suspended in sterile water.

The phrase “pharmaceutically acceptable carrier” as used herein means apharmaceutically acceptable material, composition or vehicle, such as aliquid or solid filter, diluent, excipient, solvent or encapsulatingmaterial, involved in carrying or transporting the subject regulatorsfrom one organ, or portion of the body, to another organ, or portion ofthe body. Each carrier must be “acceptable” in the sense of beingcompatible with the other ingredients of the formulation and notinjurious to the patient. Some examples of materials which can serve aspharmaceutically acceptable carriers include (1) sugars, such aslactose, glucose and sucrose; (2) starches, such as corn starch andpotato starch; (3) cellulose, and its derivatives, such as sodiumcarboxymethyl cellulose, ethyl cellulose and cellulose acetate; (4)powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients,such as cocoa butter and suppository waxes; (9) oils, such as peanutoil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil andsoybean oil; (10) glycols, such as propylene glycol; (11) polyols, suchas glycerin, sorbitol, mannitol and polyethylene glycol; (12) esterssuch as ethyl oleate and ethyl laurate; (13) agar; (14) bufferingagents, such as magnesium hydroxide and aluminum hydroxide; (15) alginicacid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer'ssolution; (19) ethyl alcohol; (20) phosphate buffer solutions; and (21)other non-toxic compatible substances employed in pharmaceuticalformulations.

As set out above, certain embodiments of the present amphetaminecompounds may contain a basic functional group, such as amino oralkylamino, and are, thus, capable of forming pharmaceuticallyacceptable salts with pharmaceutically acceptable acids. The term“pharmaceutically acceptable salts” in this respect, refers to therelatively non-toxic, inorganic and organic acid addition salts ofcompounds of the present invention. These salts can be prepared in situduring the final isolation and purification of the compounds of theinvention, or by separately reacting a purified compound of theinvention in its free base form with a suitable organic or inorganicacid, and isolating the salt thus formed. Representative salts includebut are not limited to following: 2-hydroxyethanesulfonate,2-naphthalenesulfonate, 3-hydroxy-2-naphthoate, 3-phenylpropionate,acetate, adipate, alginate, amsonate, aspartate, benzenesulfonate,benzoate, besylate, bicarbonate, bisulfate, bitartrate, borate,butyrate, calcium edetate, camphorate, camphorsulfonate, camsylate,carbonate, citrate, clavulariate, cyclopentanepropionate, digluconate,dodecylsulfate, edetate, edisylate, estolate, esylate, ethanesulfonate,fumarate, gluceptate, glucoheptanoate, gluconate, glutamate,glycerophosphate, glycollylarsanilate, hemisulfate, heptanoate,hexafluorophosphate, hexanoate, hexylresorcinate, hydrabamine,hydrobromide, hydrochloride, hydroiodide, hydroxynaphthoate, iodide,isothionate, lactate, lactobionate, laurate, laurylsulphonate, malate,maleate, mandelate, mesylate, methanesulfonate, methylbromide,methylnitrate, methylsulfate, mucate, naphthylate, napsylate,nicotinate, nitrate, N-methylglucamine ammonium salt, oleate, oxalate,palmitate, pamoate, pantothenate, pectinate, persulfate, phosphate,phosphate/diphosphate, picrate, pivalate, polygalacturonate, propionate,p-toluenesulfonate, salicylate, stearate, subacetate, succinate,sulfate, sulfosaliculate, suramate, tannate, tartrate, teoclate,thiocyanate, tosylate, triethiodide, undecanoate, and valerate salts,and the like. (See, for example, Berge et al. (1977) “PharmaceuticalSalts”, J. Pharm. Sci. 66:1-19)

In certain embodiments, the pharmaceutically acceptable salts of thesubject compounds include the conventional non-toxic salts of thecompounds, e.g., from non-toxic organic or inorganic acids. Particularlysuitable are salts of weak acids. For example, such conventionalnon-toxic salts include those derived from inorganic acids such ashydrochloric, hydrobromic, hydriodic, cinnamic, gluconic, sulfuric,sulfamic, phosphoric, nitric, and the like; and the salts prepared fromorganic acids such as acetic, propionic, succinic, glycolic, stearic,lactic, maleic, tartaric, citric, ascorbic, palmitic, maleic,hydroxymaleic, phenylacetic, glutamic, benzoic, salicyclic, sulfanilic,2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethanedisulfonic, oxalic, isothionic, and the like.

In other cases, the compounds of the present invention may contain oneor more acidic functional groups and, thus, are capable of formingpharmaceutically acceptable salts with pharmaceutically acceptablebases. The term “pharmaceutically acceptable salts” in these instancesrefers to the relatively non-toxic, inorganic and organic base additionsalts of compounds of the present invention. These salts can likewise beprepared in situ during the final isolation and purification of thecompounds, or by separately reacting the purified compound in its freeacid form with a suitable base, such as the hydroxide, carbonate orbicarbonate of a pharmaceutically acceptable metal cation, with ammonia,or with a pharmaceutically acceptable organic primary, secondary ortertiary amine. Representative alkali or alkaline earth salts includethe lithium, sodium, potassium, calcium, magnesium, and aluminum saltsand the like. Representative organic amines useful for the formation ofbase addition salts include ethylamine, diethylamine, ethylenediamine,ethanolamine, diethanolamine, piperazine and the like. (See, forexample, Berge et al., supra)

Wetting agents, emulsifiers and lubricants, such as sodium laurylsulfate and magnesium stearate, as well as coloring agents, releaseagents, coating agents, sweetening, flavoring and perfuming agents,preservatives and antioxidants can also be present in the compositions.

Examples of pharmaceutically acceptable antioxidants include: (1) watersoluble antioxidants, such as ascorbic acid, cysteine hydrochloride,sodium bisulfate, sodium metabisulfite, sodium sulfite and the like; (2)oil-soluble antioxidants, such as ascorbyl palmitate, butylatedhydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propylgallate, alpha-tocopherol, and the like; and (3) metal chelating agents,such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol,tartaric acid, phosphoric acid, and the like.

Formulations of the present invention include those suitable for oral,nasal, topical (including buccal and sublingual), rectal, vaginal and/orparenteral administration. The formulations may conveniently bepresented in unit dosage form and may be prepared by any methods wellknown in the art of pharmacy. The amount of active ingredient which canbe combined with a carrier material to produce a single dosage form willvary depending upon the host being treated, the particular mode ofadministration. The amount of active ingredient which can be combinedwith a carrier material to produce a single dosage form will generallybe that amount of the compound which produces a therapeutic effect.Generally, out of one hundred percent, this amount will range from about1 percent to about ninety-nine percent of active ingredient, preferablyfrom about 5 percent to about 70 percent, most preferably from about 10percent to about 30 percent.

Methods of preparing these formulations or compositions include the stepof bringing into association a compound of the present invention withthe carrier and, optionally, one or more accessory ingredients. Ingeneral, the formulations are prepared by uniformly and intimatelybringing into association a compound of the present invention withliquid carriers, or finely divided solid carriers, or both, and then, ifnecessary, shaping the product.

Formulations of the invention suitable for oral administration may be inthe form of capsules, cachets, pills, tablets, lozenges (using aflavored basis, usually sucrose and acacia or tragacanth), powders,granules, or as a solution or a suspension in an aqueous or non-aqueousliquid, or as an oil-in-water or water-in-oil liquid emulsion, or as anelixir or syrup, or as pastilles (using an inert base, such as gelatinand glycerin, or sucrose and acacia) and/or as mouth washes and thelike, each containing a predetermined amount of a compound of thepresent invention as an active ingredient. A compound of the presentinvention may also be administered as a bolus, electuary or paste.

In solid dosage forms of the invention for oral administration(capsules, tablets, pills, dragees, powders, granules and the like), theactive ingredient is mixed with one or more pharmaceutically acceptablecarriers, such as sodium citrate or dicalcium phosphate, and/or any ofthe following: (1) fillers or extenders, such as starches, lactose,sucrose, glucose, mannitol, and/or silicic acid; (2) binders, such as,for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose and/or acacia; (3) humectants, such as glycerol;(4) disintegrating agents, such as agar-agar, calcium carbonate, potatoor tapioca starch, alginic acid, certain silicates, and sodiumcarbonate; (5) solution retarding agents, such as paraffin; (6)absorption accelerators, such as quaternary ammonium compounds; (7)wetting agents, such as, for example, cetyl alcohol and glycerolmonostearate; (8) absorbents, such as kaolin and bentonite clay; (9)lubricants, such a talc, calcium stearate, magnesium stearate, solidpolyethylene glycols, sodium lauryl sulfate, and mixtures thereof; and(10) coloring agents. In the case of capsules, tablets and pills, thepharmaceutical compositions may also comprise buffering agents. Solidcompositions of a similar type may also be employed as fillers in softand hard-filled gelatin capsules using such excipients as lactose ormilk sugars, as well as high molecular weight polyethylene glycols andthe like.

A tablet may be made by compression or molding, optionally with one ormore accessory ingredients. Compressed tablets may be prepared usingbinder (for example, gelatin or hydroxypropylmethyl cellulose),lubricant, inert diluent, preservative, disintegrant (for example,sodium starch glycolate or cross-linked sodium carboxymethyl cellulose),surface-active or dispersing agent. Molded tablets may be made bymolding in a suitable machine a mixture of the powdered compoundmoistened with an inert liquid diluent.

The tablets, and other solid dosage forms of the pharmaceuticalcompositions of the present invention, such as dragees, capsules, pillsand granules, may optionally be scored or prepared with coatings andshells, such as enteric coatings and other coatings well known in thepharmaceutical-formulating art. They may also be formulated so as toprovide slow or controlled release of the active ingredient thereinusing, for example, hydroxypropylmethyl cellulose in varying proportionsto provide the desired release profile, other polymer matrices,liposomes and/or microspheres. They may be sterilized by, for example,filtration through a bacteria-retaining filter, or by incorporatingsterilizing agents in the form of sterile solid compositions which canbe dissolved in sterile water, or some other sterile injectable mediumimmediately before use. These compositions may also optionally containopacifying agents and may be of a composition that they release theactive ingredient(s) only, or preferentially, in a certain portion ofthe gastrointestinal tract, optionally, in a delayed manner. Examples ofembedding compositions which can be used include polymeric substancesand waxes. The active ingredient can also be in micro-encapsulated form,if appropriate, with one or more of the above-described excipients.

Liquid dosage forms for oral administration of the compounds of theinvention include pharmaceutically acceptable emulsions, microemulsions,solutions, suspensions, syrups and elixirs. In addition to the activeingredient, the liquid dosage forms may contain inert diluents commonlyused in the art, such as, for example, water or other solvents,solubilizing agents and emulsifiers, such as ethyl alcohol, isopropylalcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzylbenzoate, propylene glycol, 1,3-butylene glycol, oils (in particular,cottonseed, groundnut, corn, germ, olive, castor and sesame oils),glycerol, tetrahydrofuryl alcohol, polyethylene glycols and fatty acidesters of sorbitan, and mixtures thereof.

Besides inert diluents, the oral compositions can also include adjuvantssuch as wetting agents, emulsifying and suspending agents, sweetening,flavoring, coloring, perfuming and preservative agents.

Suspensions, in addition to the active compounds, may contain suspendingagents as, for example, ethoxylated isostearyl alcohols, polyoxyethylenesorbitol and sorbitan esters, microcrystalline cellulose, aluminummetahydroxide, bentonite, agar-agar and tragacanth, and mixturesthereof.

Formulations of the pharmaceutical compositions of the invention forrectal or vaginal administration may be presented as a suppository,which may be prepared by mixing one or more compounds of the inventionwith one or more suitable nonirritating excipients or carrierscomprising, for example, cocoa butter, polyethylene glycol, asuppository wax or a salicylate, and which is solid at room temperature,but liquid at body temperature and, therefore, will melt in the rectumor vaginal cavity and release the active amphetamine compound.

Formulations of the present invention which are suitable for vaginaladministration also include pessaries, tampons, creams, gels, pastes,foams or spray formulations containing such carriers as are known in theart to be appropriate.

Dosage forms for the topical or transdermal administration of a compoundof this invention include powders, sprays, ointments, pastes, creams,lotions, gels, solutions, patches and inhalants. The active compound maybe mixed under sterile conditions with a pharmaceutically acceptablecarrier, and with any preservatives, buffers, or propellants which maybe required.

The ointments, pastes, creams and gels may contain, in addition to anactive compound of this invention, excipients, such as animal andvegetable fats, oils, waxes, paraffins, starch, tragacanth, cellulosederivatives, polyethylene glycols, silicones, bentonites, silicic acid,talc and zinc oxide, or mixtures thereof.

Powders and sprays can contain, in addition to a compound of thisinvention, excipients such as lactose, talc, silicic acid, aluminumhydroxide, calcium silicates and polyamide powder, or mixtures of thesesubstances. Sprays can additionally contain customary propellants, suchas chlorofluorohydrocarbons and volatile unsubstituted hydrocarbons,such as butane and propane.

In certain embodiments, the subject compound(s) are formulated as partof a transdermal patch. Transdermal patches have the added advantage ofproviding controlled delivery of a compound of the present invention tothe body. Such dosage forms can be made by dissolving or dispersing theamphetamine compounds in the proper medium. Absorption enhancers canalso be used to increase the flux of the amphetamine compounds acrossthe skin. The rate of such flux can be controlled by either providing arate-controlling membrane or dispersing the compound in a polymer matrixor gel.

The “free base form” of amphetamine relates to a form in whichamphetamine is not complexed with an acid, e.g., is not an ammoniumsalt. Such forms may be incorporated into a patch. It will beappreciated that the amphetamine compounds may be complexed, forexample, with elements of the drug-retaining matrix of the patch and, assuch, the amphetamine compounds may not necessarily be in the form ofthe free base, when actually retained by the patch.

The patch preferably comprises a drug-impermeable backing layer.Suitable examples of drug-impermeable backing layers which may be usedfor transdermal or medicated patches include films or sheets ofpolyolefins, polyesters, polyurethanes, polyvinyl alcohols, polyvinylchlorides, polyvinylidene chloride, polyamides, ethylene-vinyl acetatecopolymer (EVA), ethylene-ethylacrylate copolymer (EEA), vinylacetate-vinyl chloride copolymer, cellulose acetate, ethyl cellulose,metal vapour deposited films or sheets thereof, rubber sheets or films,expanded synthetic resin sheets or films, non-woven fabrics, fabrics,knitted fabrics, paper and foils. Preferred drug-impermeable, elasticbacking materials are selected from polyethylene tereplithalate (PET),polyurethane, ethylene-vinyl acetate copolymer (EVA), plasticizedpolyvinylchloride, woven and non-woven fabric. Especially preferred isnon-woven polyethylenetereplithalate (PET). Other backings will bereadily apparent to those skilled in the art.

The term ‘block copolymer’, in the preferred adhesives of the invention,refers to a macromolecule comprised of two or more chemically dissimilarpolymer structures, terminally connected together (Block Copolymers:Overview and Critical Survey, Noshay and McGrath, 1977). Thesedissimilar polymer structures, sections or segments, represent the‘blocks’ of the block copolymer. The blocks may generally be arranged inan A-B structure, an A-B-A structure, or a multi-block -(A-B)_(n)-system, wherein A and B are the chemically distinct polymer segments ofthe block copolymer.

It is generally preferred that the block copolymer is of an A-B-Astructure, especially wherein one of A and B is an acrylic-typepolymeric unit. It will be appreciated that the present invention isalso applicable using block copolymers which possess three or moredifferent blocks, such as an A-B-C block copolymer. However, forconvenience, reference hereinafter to block copolymers will assume thatthere are only A and B sub-units, but it will be appreciated that suchreference also encompasses block copolymers having more than twodifferent sub-units, unless otherwise specified.

It will be appreciated that the properties of block copolymers are verylargely determined by the nature of the A and B blocks. Block copolymerscommonly possess both ‘hard’ and ‘soft’ segments. A ‘hard’ segment is apolymer that has a glass transition temperature (Tg) and/or a meltingtemperature (Tm) that is above room temperature, while a ‘soft’ segmentis a polymer that has a Tg (and possibly a Tm) below room temperature.The different segments are thought to impart different properties to theblock copolymer. Without being constrained by theory, it is thought thatassociation of the hard segments of separate block copolymer unitsresult in physical cross-links within the block copolymer, therebypromoting cohesive properties of the block copolymer. It is particularlypreferred that the hard segments of the block copolymers form suchphysical close associations.

The block copolymers useful in the present invention preferably areacrylic block copolymers. In acrylic block copolymers, at least one ofthe blocks of the block copolymer is an acrylic acid polymer, or apolymer of an acrylic acid derivative. The polymer may be composed ofjust one repeated monomer species. However, it will be appreciated thata mixture of monomeric species may be used to form each of the blocks,so that a block may, in itself, be a copolymer. The use of a combinationof different monomers can affect various properties of the resultingblock copolymer. In particular, variation in the ratio or nature of themonomers used allows properties such as adhesion, tack and cohesion tobe modulated, so that it is generally advantageous for the soft segmentsof the block copolymer to be composed of more than one monomer species.

It is preferred that alkyl acrylates and alkyl methacrylates arepolymerized to form the soft portion of the block copolymer. Alkylacrylates and alkyl methacrylates are thought to provide properties oftack and adhesion. Suitable alkyl acrylates and alkyl methacrylatesinclude n-butyl acrylate, n-butyl methacrylate, hexyl acrylate,2-ethylbutyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate,2-ethylhexyl methacrylate, decyl acrylate, decyl methacrylate, dodecylacrylate, dodecyl methacrylate, tridecylacrylate and tridecylmethacrylate, although other suitable acrylates and methacrylates willbe readily apparent to those skilled in the art. It is preferred thatthe acrylic block copolymer comprises at least 50% by weight of alkylacrylate or alkyl methacrylate(co)polymer.

Variation in the components of the soft segment affects the overallproperties of the block copolymer, although the essential featureremains the cross-linking of the soft segments. For example, softsegments essentially consisting of diacetone acrylamide with eitherbutyl acrylate and/or 2-ethylhexyl acrylate, in approximately equalproportions, work well, and a ratio by weight of about 3:4:4 providesgood results. It is preferred that diacetone acrylamide, or other polarmonomer, such as hydroxyethylmethacrylate or vinyl acetate, be presentin no more than 50% w/w of the monomeric mix of the soft segment, asthis can lead to reduced adhesion, for example. The acrylate componentmay generally be varied more freely, with good results observed withboth2-ethylhexyl acrylate and butyl acrylate together or individually.

As noted above, ratios of the various monomers are generally preferredto be approximately equal. For adhesives, this is preferred to be with apolar component of 50% or less of the soft segment, with the apolarportion forming up to about 85% w/w, but preferably between about 50 and70% w/w. In the example above, this is about 72% (4+4) a polar to about18% (3) polar.

In general, it is particularly preferred that any apolar monomer useddoes not confer acidity on the adhesive. Adhesives of the invention arepreferably essentially neutral, and this avoids any unnecessarydegeneration of the amphetamine compounds.

Limiting active functionalities, especially those with active hydrogen,is generally preferred, in order to permit wide use of any givenformulation of adhesive without having to take into account how it islikely to interact, chemically, with its environment. Thus, a generallychemically inert adhesive is preferred, in the absence of requirementsto the contrary.

As discussed above, polymers suitable for use as the hard portion of theblock copolymer possess glass transition temperatures above roomtemperature. Suitable monomers for use in forming the hard segmentpolymer include styrene, (x-methylstyrene, methyl methacrylate and vinylpyrrolidone, although other suitable monomers will be readily apparentto those skilled in the art. Styrene and polymethylmethacrylate havebeen found to be suitable for use in the formation of the hard segmentof the block copolymers. It is preferred that the hard portion of theblock copolymer forms from 3-30% w/w of the total block copolymer,particularly preferably from 5-15% w/w.

The block copolymer is further characterized in that the soft portionscontain a degree of chemical cross-linking. Such cross-linking may beeffected by any suitable cross-linking agent. It is particularlypreferable that the cross-linking agent be in the form of a monomersuitable for incorporation into the soft segment during polymerization.Preferably the cross-linking agent has two, or more, radicallypolymerizable groups, such as a vinyl group, per molecule of themonomer, at least one tending to remain unchanged during the initialpolymerization, thereby to permit cross-linking of the resulting blockcopolymer.

Suitable cross-linking agents for use in the present invention includedivinylbenzene, methylene bis-acrylamide, ethylene glycoldi(meth)acrylate, ethyleneglycol tetra(meth)acrylate, propylene glycoldi(meth)acrylate, butylene glycoldi(meth)acrylate, or trimethylolpropanetri(meth)acrylate, although other suitable cross-linking agents will bereadily apparent to those skilled in the art. A preferred cross-linkingagent is tetraethylene glycol dimethacrylate. It is preferred that thecross-linking agent comprises between about 0.01 to about 0.6% by weightof the block copolymer, with between about 0.1 to about 0.4% by weightbeing particularly preferred.

Methods for the production of block copolymers from their monomericconstituents are well known. The block copolymer portions of the presentinvention may be produced by any suitable method, such as step growth,anionic, cationic and free radical methods (Block Copolymers, supra).Free radical methods are generally preferred over other methods, such asanionic polymerization, as the solvent and the monomer do not have to bepurified.

Suitable initiators for polymerization include polymeric peroxides withmore than one peroxide moiety per molecule. An appropriate choice ofreaction conditions is well within the skill of one in the art, once asuitable initiator has been chosen.

The initiator is preferably used in an amount of about 0.005 to about0.1% by weight of the block copolymer, with about 0.01 to about 0.05% byweight being particularly preferred, although it will be appreciatedthat the amount chosen is, again, well within the skill of one in theart. In particular, it is preferred that the amount should not be somuch as to cause instant gelling of the mix, nor so low as to slow downpolymerization and to leave excess residual monomers. A preferred levelof residual monomers is below about 2000 ppm.

It will also be appreciated that the amount of initiator will varysubstantially, depending on such considerations as the initiator itselfand the nature of the monomers.

The block copolymers are adhesives, and preferably are pressuresensitive adhesives. Pressure sensitive adhesives can be applied to asurface by hand pressure and require no activation by heat, water orsolvent. As such, they are particularly suitable for use in accordancewith the present invention.

The block copolymers may be used without tackifiers and, as such; areparticularly advantageous. However, it will be appreciated that theblock copolymers may also be used in combination with a tackifier, toprovide improved tack, should one be required or desired. Suitabletackifiers are well known and will be readily apparent to those skilledin the art.

Without being constrained by theory, it is thought that the combinationof chemical cross-links between the soft segments of the copolymercombined with the, generally, hydrophobic interaction, or physicalcross-linking, between the hard portions results in a “matrix-like”structure. Copolymers having only physical cross-linking of the hardsegments are less able to form such a matrix. It is believed that thecombination of both forms of cross-linking of the block copolymersprovides good internal strength (cohesion) and also high drug storagecapacity.

More particularly, it is believed that the hard segments associate toform “islands”, or nodes, with the soft segments radiating from andbetween these nodes.

There is a defined physical structure in the “sea” between the islands,where the soft segments are cross-linked, so that there is no necessityfor extensive intermingling of the soft segments. This results in agreater cohesion of the whole block copolymer while, at the same time,allowing shortened soft segment length and still having as great, orgreater, distances between the islands, thereby permitting good drugstorage capacity.

The block copolymer preferably cross-links as the solvent is removed, sothat cross-linking can be timed to occur after coating, this being thepreferred method.

Accordingly, not only can the block copolymer easily be coated onto asurface, but the complete solution can also be stored for a periodbefore coating. Accordingly, in the manufacturing process of thepatches, the process preferably comprises polymerizing the monomericconstituents of each soft segment in solution, then adding theconstituents of the hard segment to each resulting solution andpolymerizing the resulting mix, followed by cross-linking by removal ofany solvent or solvent system, such as by evaporation. If the solutionis to be stored for any length of time, it may be necessary to keep thepolymer from precipitating out, and this may be achieved by known means,such as by suspending agents or shaking. It may also be necessary toselect the type of polymers that will be subject to substantially nocross-linking until the solvent is evaporated.

In general, it is preferred that the adhesive possesses a minimum numberof functionalities having active hydrogen, in order to avoid undesirablereactions/interactions, such as with any drug that it is desired toincorporate into the adhesive material. It will be appreciated that thisis only a preferred restriction, and that any adhesive may be tailoredby one skilled in the art to suit individual requirements.

Suitable monomers for use in forming the hard segment include styrene,a-methylstyrene, methyl methacrylate and vinyl pyrrolidone, with thepreferred proportion of the hard segment being between about 5 to about15 percent (w/w). In particular, it is advantageous to use the compoundsof WO 99/02141, as it is possible to load over about 30 percent of druginto such a system.

Thus, in the patches of the present invention, it is generally possibleto calculate the amount of drug required and determine the appropriatepatch size with a given drug loading in accordance with a patient's bodyweight, and this can be readily calculated by those skilled in the art.

In certain embodiments, small amounts of plasticizer, such as isopropylmyristate (IPM), are incorporated. This has the advantage of helping tosolubilize the amphetamine as well as rendering the adhesive less roughon the skin. Levels of between about 2 to about 25%, by weight, aregenerally useful, with levels of between about 3 to about 20% being morepreferred and levels of about 5 to about 15%, especially about 10%,being most preferred. Other plasticizers may also be used, and suitableplasticizers will be readily apparent to those skilled in the art.

Plasticizers generally take the form of oily substances introduced intothe adhesive polymer. The effect of the introduction of such oilysubstances is to soften the physical structure of the adhesive whilst,at the same time, acting at the interface between the adhesive and theskin, thereby helping to somewhat weaken the adhesive, and to reduceexfoliation.

The free base oil may be obtained by basifying amphetamine salts, or anyother suitable salt, with a suitable base, in the presence of ahydrophilic solvent, especially water, and an organic solvent. Forinstance, water and ethyl acetate, in approximately equal proportions,work well, with ammonia serving as the basifying agent. The water maythen be removed and the preparation washed with further water, or otheraqueous preparation, after which the preparation may be suitablyextracted with ether, for example, after having removed the ethylacetate. It is preferred to keep the preparation under an inertatmosphere, especially after completion.

Whilst it will be appreciated that patches of the present invention maybe removed from the patient at any time, once it is desired to terminatea given dose, this can have the disadvantage of providing an opportunityfor potential drug abuse of the partially discharged patch. Abuse ofamphetamines is highly undesirable.

In certain embodiments, it may be advantage to use a patch tailored tohave delivered the majority of the amphetamine that it is capable ofdelivering, in a 24 hour period, by about 8 hours after application, sothat a patch can be left in place, and levels of drug still diminishappreciably. It is advantageous that the drug delivery profile has firstorder kinetics, so that the majority of the drug is delivered during themain part of the day and, even if the patient omits to remove the patch,the drug is moving towards exhaustion by the end of the day, and theamount of drug is dropping rapidly.

It will be appreciated that patches of the invention may be constructedin any suitable manner known in the art for the manufacture oftransdermal patches. The patches may simply comprise adhesive, drug andbacking, or may be more complex, such as having edging to preventseepage of drug out of the sides of the patch. Patches may also bemulti-layered.

Ophthalmic formulations, eye ointments, powders, solutions and the like,are also contemplated as being within the scope of this invention.

Pharmaceutical compositions of this invention suitable for parenteraladministration comprise one or more compounds of the invention incombination with one or more pharmaceutically acceptable sterileisotonic aqueous or nonaqueous solutions, dispersions, suspensions oremulsions, or sterile powders which may be reconstituted into sterileinjectable solutions or dispersions just prior to use, which may containantioxidants, buffers, bacteriostats, solutes which render theformulation isotonic with the blood of the intended recipient orsuspending or thickening agents.

Examples of suitable aqueous and nonaqueous carriers which may beemployed in the pharmaceutical compositions of the invention includewater, ethanol, polyols (such as glycerol, propylene glycol,polyethylene glycol, and the like), and suitable mixtures thereof,vegetable oils, such as olive oil, and injectable organic esters, suchas ethyl oleate. Proper fluidity can be maintained, for example, by theuse of coating materials, such as lecithin, by the maintenance of therequired particle size in the case of dispersions, and by the use ofsurfactants.

These compositions may also contain adjuvants such as preservatives,wetting agents, emulsifying agents and dispersing agents. Prevention ofthe action of microorganisms may be ensured by the inclusion of variousantibacterial and antifungal agents, for example, paraben,chlorobutanol, phenol sorbic acid, and the like. It may also bedesirable to include isotonic agents, such as sugars, sodium chloride,and the like into the compositions. In addition, prolonged absorption ofthe injectable pharmaceutical form may be brought about by the inclusionof agents which delay absorption such as aluminum monostearate andgelatin.

In some cases, in order to prolong the effect of a drug, it is desirableto slow the absorption of the drug from subcutaneous or intramuscularinjection. This may be accomplished by the use of a liquid suspension ofcrystalline or amorphous material having poor water solubility. The rateof absorption of the drug then depends upon its rate of dissolutionwhich, in turn, may depend upon crystal size and crystalline form.Alternatively, delayed absorption of a parenterally administered drugform is accomplished by dissolving or suspending the drug in an oilvehicle.

Injectable depot forms are made by forming microencapsule matrices ofthe subject compounds in biodegradable polymers such aspolylactide-polyglycolide. Depending on the ratio of drug to polymer,and the nature of the particular polymer employed, the rate of drugrelease can be controlled. Examples of other biodegradable polymersinclude poly(orthoesters) and poly(anhydrides). Depot injectableformulations are also prepared by entrapping the drug in liposomes ormicroemulsions which are compatible with body tissue.

When the compounds of the present invention are administered aspharmaceuticals, to humans and animals, they can be given per se or as apharmaceutical composition containing, for example, about 0.1 to about99.5% (more preferably, about 0.5 to about 90%) of active ingredient incombination with a pharmaceutically acceptable carrier.

The addition of the active compound of the invention to animal feed ispreferably accomplished by preparing an appropriate feed premixcontaining the active compound in an effective amount and incorporatingthe premix into the complete ration.

Alternatively, an intermediate concentrate or feed supplement containingthe active ingredient can be blended into the feed. The way in whichsuch feed premixes and complete rations can be prepared and administeredare described in reference books (such as “Applied Animal Nutrition”,W.H. Freedman and Co., San Francisco, U.S.A., 1969 or “Livestock Feedsand Feeding” 0 and B books, Corvallis, Ore., U.S.A., 1977).

Exemplary Uses of the Compounds of the Invention.

In various embodiments, the present invention contemplates modes oftreatment and prophylaxis which utilize one or more of the amphetaminecompounds. These agents may be useful for increasing the occurrence ofmemory consolidation or decreasing or preventing the effects of defectsin an animal which mitigate memory consolidation. In other embodiments,the preparations of the present invention can be used simply to enhancenormal memory function.

In various other embodiments, the present invention contemplates modesof treatment and prophylaxis which utilize one or more of the subjectamphetamine compounds to alter defects in attention span and/or focus inan organism. The enhancement and/or restoration of attention span in anorganism has positive behavioral, social, and psychologicalconsequences. Additionally, enhancement of attention span can improvememory and learning.

In certain embodiments, the subject method can be used to treat patientswho have been diagnosed as having or at risk of developing disorders inwhich diminished declarative memory is a symptom, e.g., as opposed toprocedural memory. The subject method can also be used to treat normalindividuals for whom improved declarative memory is desired.

Memory disorders which can be treated according to the present inventionmay have a number of origins: a functional mechanism (anxiety,depression), physiological aging (age-associated memory impairment, mildcognitive impairment, etc.), drugs, or anatomical lesions (dementia).Indications for which such preparations may be useful include learningdisabilities, memory impairment, e.g., due to toxicant exposure, braininjury, brain aneurysm, age, schizophrenia, epilepsy, mental retardationin children, and senile dementia, including Alzheimer's disease.

In certain embodiments, the invention contemplates the treatment ofamnesia. Amnesias are described as specific defects in declarativememory. Faithful encoding of memory requires a registration, rehearsal,and retention of information. The first two elements appear to involvethe hippocampus and medial temporal lobe structures. The retention orstorage appears to involve the heteromodal association areas. Amnesiacan be experienced as a loss of stored memory or an inability to formnew memories. The loss of stored memories is known as retrogradeamnesia. The inability to form new memories is known as anterogradeamnesia.

Complaints of memory problems are common. Poor concentration, poorarousal and poor attention all may disrupt the memory process to adegree. The subjective complaint of memory problems therefore must bedistinguished from true amnesias. This is usually done at the bedside ina more gross evaluation and through specific neuropsychological tests.Defects in visual and verbal memory can be separated through such tests.In amnesias there is by definition a preservation of other mentalcapacities such as logic. The neurobiologic theory of memory describedabove would predict that amnesias would have relatively fewpathobiologic variations. Clinically the problem of amnesias oftenappears as a result of a sudden illness in an otherwise healthy person.

Exemplary forms of amnesias which may be treated by the subject methodinclude amnesias of short duration, alcoholic blackouts,Wernicke-Korsakoffs (early), partial complex seizures, transient globalamnesia, those which are related to medication, such as triazolam(Halcion), and basilar artery migraines. The subject method may also beused to treat amnesias of longer duration, such as post concussive or asthe result of Herpes simplex encephalitis.

In certain embodiments, this invention contemplates the treatment of theAnterior Communicating Artery Syndrome. This syndrome is prevalent amongsurvivors of Anterior Communicating artery aneurysms and often includesanterograde amnesia, a specific deficit in new memory formation, withrelative sparing of older memories as well as intelligence andattention. The Anterior Communicating Artery Syndrome may also includesome personality changes and confabulation. There is a considerableanatomic and clinical evidence that the Anterior Communicating ArterySyndrome in man is a result of a focal lesion in the basal forebrainarea (particularly the medial septal area), secondary to combined damagefrom the aneurysm and the surgical or endovascular treatment of theaneurysm.

In addition, the compounds of the invention enhance memory in normalindividuals, in particular, memory consolidation in humans.

The present invention is further illustrated by the following examples,which are not intended to be limiting in any way.

EXEMPLIFICATION

The invention now being generally described, it will be more readilyunderstood by reference to the following examples which are includedmerely for purposes of illustration of certain aspects and embodimentsof the present invention, and are not intended to limit the invention.

The Inhibitory Avoidance (IA) task (also referred to herein as “PassiveAvoidance”) (Bammer, G., Neurosci & Biobev. Rev. 6:247-296 (1982)) andthe Spontaneous Object Recognition (SOR) task (Ennaceur, A., et al.,Psychopharmacol. 109:321-330 (1992); Ennaceur, A., et al., Behav. BrainRes. 33:197-207 (1989)) are well-studied behavioral paradigms which canprovide the researcher with a consistent and long lasting measure ofmemory. The paradigms consists of one training trial and one retentiontrial. Test substances may be administered to the rats either before orafter training. Improved memory, as a result of test substanceadministration, is evident on the retention trial. The objective of thefollowing experiments was to investigate the effects of amphetamine onIA and SOR memory in the rat.

General Experimental Procedures

Inhibitory Avoidance

The Inhibitory Avoidance apparatus (Coulbourn Instruments) consisted ofa light chamber and a dark chamber, which were joined by means of asliding guillotine door. The floor of the dark compartment consisted of2.4 mm diameter steel rods, through which a foot-shock could beadministered to the animal by a constant current 18-pole shockscrambler. The test apparatus was enclosed in a ventilated,sound-attenuating cabinet, and was controlled by Graphic State™ NotationSoftware (Version 1.013) and a Hewlett Packard Pavilion Computer.Training involved the rat being placed in the light chamber for a tensecond period, after which time the sliding door was opened, allowingthe rat access to the dark chamber. Two seconds after entering the darkchamber, a continuous 0.46 mA foot-shock was delivered through the floorgrid for two seconds. The animal was then removed from the apparatus andreturned to the home cage. The animals received a retention test 24hours following training. The retention test was identical to trainingexcept that no foot-shock was delivered. Latency to enter the darkchamber was recorded, and the animals were then returned to their homecages. Data was collected by the Graphic State™ Notation software, andwas recorded onto an appropriate data sheet.

Spontaneous Object Recognition

Apparatus for Object Recognition testing consisted of a plexiglass openfield activity chamber, measuring 30 by 30 cm. A video camera wasmounted on the wall above the chamber. Three plastic objects served asstimuli for the experiment. Two of the objects were identical to oneanother, and the third was different. Rats were individually habituatedto the open-field box for three consecutive days. Habituation sessionswere six minutes in duration. Twenty-four hours after the last day ofhabituation, a training session was conducted, in which two identicalobjects were placed in the open-field box, 10 cm from the back wall. Theanimal was placed into the box and was allowed to explore freely for aperiod of four minutes. Twenty-four hours after the training session,retention testing was conducted. During retention testing, the rat wasplaced back into the same activity box with one of the familiar objectsused during the training session and a novel object that the rat had notseen before. The rat was allowed to explore the box and objects for aperiod of four minutes. Testing was conducted at the same time each day,and was videotaped for off-line analysis. Two discrimination indices, D1and D2 were calculated in order to measure the strength of recognitionmemory. D1 reflects the amount of time spent exploring the novel objectminus the amount of time spent exploring the familiar object, and D2reflects D1 divided by total exploration time.

Activity Monitoring

Activity monitoring was conducted in a Plexiblas open-field box.Activity levels were measured by a grid of infrared light beams thattraversed the cage from left to right and back to front. The location ofthe animal was detected by breaks in the infrared light beams. Generalbehavior and activity levels were recorded by a computerized monitoringsystem for a period of ten minutes. The analyzed behaviors included butwere not limited to; horizontal activity, total distance moved, movementtime, number of movements, number of rears, number of stereotypedmovements, and time spent resting. Data was collected on-line usingVersa Max (Version 1.83) computer software and a Hewlett PackardPavilion computer.

Tail Flick

For Tail-Flick Analgesia Testing, the animal was placed on top of theTail-Flick monitor and gently held in place with a cotton towel. Thetail of the animal was placed in a shallow groove lying between twosensors and over the top of a radiant heat wire. The Tail Flick monitorwas activated, and the latency for the animal to flick its tail out ofthe groove and away from the heat source was recorded. The animal wasreturned to its home cage immediately following testing.

Formix Lesions

Rats were anesthetized with Nembutal (55 mg/kg) and prepared forsurgery. The rat was placed in the stereotaxic apparatus, a midlineincision made, and the scalp retracted to expose the skull. The skullwas cleaned and dried using sterile saline and cotton swabs, and fourstereotaxically determined holes were drilled in the skull at thefollowing coordinates: 0.3 and 0.8 mm posterior to Bregma, and 0.5 and0.7 mm lateral to the midline. An electrode (Teflon-coated wire, 125 μmin diameter) was lowered into the brain to a depth of 4.6 mm, and DCcurrent at 1.0 mA was passed through the electrodes for a duration of 10seconds. The electrodes were then removed, and the wound was sutured.Animals were removed from the stereotaxic apparatus and receivedpostoperative care and monitoring until fully conscious. The rats wereleft to recover for a period of seven days prior to behavioral testing.The health status of the animals was checked on a daily basis during therecovery period.

Example 1 Dose Response Testing

Effects of (S)-(+)-amphetamine on Inhibitory Avoidance

In this experiment, rats were injected with three different doses of(S)-(+) amphetamine thirty minutes prior to being trained on the IAtask. As can be seen from FIG. 1, a dose of about 2 mg/kg of amphetamineimproved retention of the task, while doses of about 0.25, about 0.50and about 1.0 mg/kg had no effect. In order to verify this result, asecond experiment was conducted. Rats were injected with about 2.0 mg/kgof amphetamine and trained on the IA task. As can be seen from FIG. 2,this dose of (S)-(+)-amphetamine significantly improved retention of thetask. An unpaired t-test demonstrated that this enhancement wasstatistically significant (p<0.01).

Effects of (R)-(−)-amphetamine (C105) on Inhibitory Avoidance

The first experiment to be conducted using C105 was a dose responseexperiment, in which different doses of C105 (about 0.4, about 0.5,about 0.75, 1.0 and about 2.0 mg/kg) were administered to the rats onehour prior to training on the Inhibitory Avoidance task. Retention forthe task was tested 24-hours later. A one way ANOVA was conducted on thedata, and the results revealed a statistically significant differencebetween the dose level groups (F(5,59)=3.368, p<0.01). Subsequent posthoc analysis (Student Newman Keuls) demonstrated that the 1.0 mg/kggroup performed significantly better than saline injected controls(p<0.05). The 0.5 mg/kg dose also appeared to be effective in enhancingthe animals performance, however, this trend did not reach statisticalsignificance. This experiment was subsequently replicated using 0.5mg/kg as the target dose in order to verify this result (see section9.1.4). Dose Response data is presented individually in Table 3.

Effects of (R)-(−)-amphetamine (C105) on Inhibitory Avoidance

In this experiment, four groups of 10 rats were injected with differentdoses (0.5 mg/kg, 1.0 mg/kg, 2.0 mg/kg or 4.0 mg/kg) of the R-(−)enantiomer of amphetamine one hour prior to being trained on the IAtask. The experiments were conducted with a 24 hour retention intervaland a 0.46 mA shock intensity. As can be seen in FIG. 8, a much lowerdose of (R)-(−)-amphetamine is required for the same improved retentioneffect as obtained with (S)-(+)-amphetamine (compare to FIG. 1).Increasing the dose above 0.5 kg/mg did not further improve theretention results obtained with this dose possibly indicating asaturation effect.

Effects of (R)-(−)-amphetamine (C105) on Inhibitory Avoidance

In order to investigate whether doses of C105 lower than 0.5 mg/kgenhanced performance, rats were injected with 0.1, 0.25 or 0.5 mg/kg ofC105 one hour prior to training. Retention was tested 24-hours later.This experiment revealed that doses of C105 lower than 0.5 mg/kg werenot effective in improving the mnemonic performance of the rats. Incontrast, the 0.5 mg/kg dose significantly enhanced performance on thetask (F(3,39)=67450, p<0.0477). These data are presented individually inTable 4.

Example 2 Time Course of Effectiveness

In this experiment, the time of drug administration was varied in orderto determine the optimal pre-training drug administration time. FIG. 3shows that (S)-(+) amphetamine (2.0 mg/kg) is effective whenadministered to the rats between 0 and 2 hours prior to training.

Example 3 Long Term Retention

This experiment was conducted in order to determine whether the enhancedretention observed in Experiment 2 was long-lasting. Rats received asecond retention test one week after the first retention test. Noadditional training or drug was administered to the animals in theinterim period. FIG. 4 illustrates that rats that had received(S)-(+)-amphetamine the previous week performed significantly betterthan rats that had received control injections of vehicle solution.(F(4,47)=3.688, p<0.01).

Example 4 Effects on Lesioned Animals

Effects of (−)(+)-amphetamine on Lesioned Animals

The findings of the above experiments are important, as they identifythe most effective dose and time of administration for this compound.Moreover, the results demonstrate that (S)-(+)-amphetamine improvesmemory in normal rats, and that this improvement is long-lasting. In thenext experiment, we investigated whether the performance of amnesic ratscould be improved by administration of d-amphetamine. In thisexperiment, control rats and rats with lesions of the fornix receivedinjections of either saline or d-amphetamine (2.0 mg/kg), and one hourlater, were tested on the IA task.

As FIG. 5 illustrates, (S)-(+)-amphetamine dramatically enhanced theperformance of normal rats and in addition, appeared to improve theperformance of the formix lesion rats. A one way ANOVA demonstrated thatthere was a significant difference between the performance of the fourgroups (F(3,36)=8.687, p<0.002). Student-Newman-Keuls post hoc testsrevealed firstly that the performance of normal rats that received(S)-(+)-amphetamine was significantly enhanced relative to all otherexperimental groups (p<0.05). In addition, the performance of formixanimals that received (S)-(+)-amphetamine was not significantlydifferent from normal, saline injected animals. These resultsdemonstrate that amphetamine is capable of enhancing memory in normalrats and has beneficial effects in brain damaged, amnesic rats.

Effects of (R)-(−)-amphetamine on Lesioned Animals

Rats with bilateral lesions of the formix were tested on the InhibitoryAvoidance task. All rats were injected with test (0.5, 1.0, 2.0 and 4.0mg/kg) or control article one hour prior to testing. A one-way ANOVAdemonstrated that there was a significant main effect of dose(F(4,45)=15580, p<0.0316). A dose of 1.0 mg/kg of C105 appeared to bemost effective in improving the performance of the formix lesionanimals. Data from this experiment are illustrated in FIG. 12 andpresented individually in Table 7.

Rats with lesions of the formix were also tested on the ObjectRecognition task. Rats received I.P injections of C105 (1.0 mg/kg) orsaline immediately after the training session, and were tested forretention 24-hours later. As can be seen from FIG. 13, when comparedwith controls, lesions of the formix had a detrimental effect onperformance of this task. Administration of C105 produced a trendtowards improving discrimination performance in D1 (p=0.0685), andslightly improved performance in D2.

Example 5 Effects of (R)-(−) vs. (S)-(+)Amphetamine Enantiomers onStimulation of Memory Consolidation

The effects of the (R)-(−)-amphetamine and the (S)-(+) amphetamineenantiomers on stimulation of memory consolidation and motor stimulationwere compared. The (R)-(−) enantiomer of amphetamine is referred to asC105 in the figures.

Effects of (S)-(+)-amphetamine on Inhibitory Avoidance

An experiment was conducted in which different doses of(S)-(+)-amphetamine were administered to rats one hour before trainingon the Inhibitory Avoidance task and were compared to a control group ofrats injected with saline. Retention for the task was tested 24 hourslater with a 0.46 mA shock intensity. Results for this experiment arepresented individually in Tables 1 and 2, and demonstrated that(S)-(+)-amphetamine appeared to enhance performance when administered ata dose of 2.0 mg/kg. The experiment was subsequently replicated severaltimes using a test-article dose of 2.0 mg/kg. Results from theseexperiments are represented in FIG. 6, and demonstrate that(S)-(+)-amphetamine significantly enhanced memory for the InhibitoryAvoidance task (t (76)=3.416, p<0.001). These results are in agreementwith previous research and help to demonstrate the effectiveness of(S)-(+)-amphetamine as a memory-enhancing drug.

Effects of (R)-(−)-amphetamine (C105) on Inhibitory Avoidance

In order to verify the results from the dose response test, a secondexperiment with (R)-(−)-amphetamine was conducted. Eighteen rats wereinjected with a dose of 0.5 mg/kg of (R)-(−)-amphetamine one hour priorto being trained on the IA task. The (R)-(−) amphetamine treated ratswere compared to control rats injected with saline. The experiments wereconducted with a 24 hour retention interval and a 0.46 mA shockintensity. As can be seen in FIG. 9, this dose of (R)-(−)-amphetaminesignificantly improved retention of the task. An unpaired t-testdemonstrated that this enhancement was statistically significant(p<0.002).

Based on the results obtained from the experiments described above,several more experiments were conducted investigating the effects of a0.5 mg/kg dose of C105 on Inhibitory Avoidance. The data presented inFIG. 10, and individually in Table 5, represent a summary of all suchexperiments. The results of these experiments clearly demonstrate amemory enhancing effect as measured by the Inhibitory Avoidance task.Rats that had been injected with C105 (0.5 mg/kg) one hour prior totraining performed significantly better than control animals on the24-hour retention test (t (132)=3.438, p<0.0008).

Effects of (R)-(−)-amphetamine (C105) on Object Recognition

In order to investigate the effects of C105 on recognition memory, ratswere trained on the Spontaneous Object Recognition task. Normal ratswere injected with 0.5 mg/kg C105 immediately following the trainingsession, and were tested for retention 24-hours later. The results ofthe experiment indicate that C105 significantly improved recognitionmemory. Rats that had received injections of test article immediatelyafter the training session, performed significantly better than theirsaline injected counterparts, as they spent more time exploring thenovel object during retention testing. Both discrimination indices, D1and D2, which reflect discrimination between the familiar and novelobject, were significantly higher in C105 treated animals [(t(51)=2.526,p<0.0147) and (t(51)=3.197, p<0.0024) respectively]. These results areparticularly interesting, as recognition memory is the process by whicha subject is aware that a stimulus has previously been experienced. Thisprocess requires that incoming stimuli be identified and compared withrepresentations of previously encountered stimuli stored in memory.Recognition memory is used during everyday life and failures ofrecognition memory undoubtedly contribute to the problems encountered byamnesic patients. Results from this experiment are presented in FIG. 13,and individual data are presented in Table 8.

It is interesting at this point to compare the results obtained with(R)-(−)-amphetamine (C105) to those obtained with (S)-(+)-amphetamine.(S)-(+)-Amphetamine had a memory enhancing effect at a dose of 2.0mg/kg, while (R)-(−)-amphetamine had a memory enhancing effect on thesame task at a dose of 0.5 mg/kg. Although definitive dose-responserelationship experiments between these two compounds have not beenconducted, it seems likely that C105 is a more potent memory enhancerfor this particular task in rats. It should be noted however, that themaximal efficacy of the two compounds are the same.

Example 6 Effects of (R)-(−) vs. (S)-(+)-Amphetamine on MotorStimulation

Effects of (S)-(+)-amphetamine on Activity Levels

In order to provide a comparison point for the results described above,a second experiment was conducted in which rats were injected with 2mg/kg of (S)-(+)-amphetamine prior to activity testing. Results for thisexperiment are presented in FIG. 7. The results demonstrated that(S)-(+)-amphetamine produced a clear and significant enhancement inlocomotor activity for the entire 10 minute session. Significant maineffects for the variables of total distance (F(9, 70)=1514000,p<0.0001); number of movements (F(9,70)=45.89, p<0.0001); movement time(F(9,70)=53.07, p<0.0001); rears (F(9,70)=49.47, p<0.0001), stereotypedmovements (F(9,70)=24.65, p<0.0001) and rest time (F(9,70)=44.34,p<0.0001) were observed. No significant effects of time or time-druginteractions were observed.

Effects of (R)-(−)-amphetamine (C105) on Activity Levels

In this experiment, rats were injected with 0.5 mg/kg of(R)-(−)-amphetamine (C105) and compared to a control group of ratsinjected with saline. Rat activity was monitored for a 10 minute periodone hour after (R)-(−)-amphetamine injection. As can be seen in FIG. 14,treatment with (R)-(−)-amphetamine had no significant effects on theactivity levels of the rats as compared to the control group.

This data indicates that (R)-(−)-amphetamine can provide improved memoryconsolidation without producing the motor stimulatory effects observedin the (S)-(+)-amphetamine treated rats (compare to FIG. 7). Acomparison of the results obtained for (S)-(+)-versus(R)-(−)-amphetamine indicates that (S)-(+)-amphetamine produced a largerlocomotor effect than (R)-(−)-amphetamine, at doses that are equallyeffective in enhancing memory. This observation is consistent withprevious research, which has repeatedly demonstrated that(S)-(+)-amphetamine is between 4 and 10 times more potent than(R)-(−)-amphetamine in producing elevated locomotor responses.

Example 7 Tail Flick

Tail Flick Analgesia data is presented in FIG. 16, and individual datain Table 12. Administration of 1.0, 2.0, 4.0 or 8.0 mg/kg of C105 onehour prior to testing resulted in varying degrees of analgesia. 1.0 and2.0 mg/kg had no analgesic properties, while 4.0 and 8.0 did.Statistical significance was observed at the 4.0 mg/kg dose(F(4,39)=43.18, p<0.0117). This experiment indicates that thetherapeutic dose of (R)-(−)-amphetamine had no effect on analgesia, asmeasured by the tail-flick analgesiometer.

Example 8 Post Training Administration

While the results described above provide evidence to suggest that C105enhances memory, it is possible that these results are due tonon-mnemonic factors. Because the drug was administered prior totraining, it is possible that learning or acquisitional processes wereaffected by drug administration. For this reason, a post trainingexperiment was conducted in which C105 was administered to the ratsimmediately after the training session. Injecting the drug after thetraining session affects memory consolidation rather than acquisition,primarily because the drug is not on board at the time of training. Theresults of this experiment are represented in FIG. 11 and presentedindividually in Table 6. As can be seen from FIG. 11, post trainingadministration of 0.5 mg/kg of C105 significantly enhanced performanceon the Inhibitory Avoidance task (t(26)=2.160, p<0.0402). Thisexperiment therefore, provides strong evidence that C105 works byselectively enhancing memory consolidation. TABLE 1 Effects of DifferentDoses of S-(+)-Amphetamine on Inhibitory Avoidance Saline 0.25 mg/kg 0.5mg/kg 1.0 mg/kg 2.0 mg/kg 22.0 6.0 2.0 7.0 33.0 25.0 19.0 26.0 17.0 63.026.0 29.0 38.0 19.0 82.0 33.0 29.0 39.0 25.0 84.0 41.0 44.0 63.0 31.0101.0 71.0 59.0 65.0 34.0 190.0 121.0 94.0 110.0 35.0 230.0 216.0 124.0153.0 47.0 245.0 234.0 310.0 207.0 157.0 457.0 358.0 452.0 207.0 263.0517.0Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal (10 animals per treatment group).Data is rank-ordered.

TABLE 2 Summary of Effects of S-(+)-Amphetamine (2.0 mg/kg) onInhibitory Avoidance Saline S-(+)-Amphetamine 3.0 5.0 6.0 15.0 11.0 26.017.0 32.0 19.0 33.0 22.0 60.0 25.0 63.0 26.0 82.0 30.0 84.0 33.0 100.033.0 101.0 33.0 127.0 36.0 148.0 40.0 167.0 41.0 169.0 42.0 188.0 44.0190.0 53.0 201.0 53.0 204.0 57.0 222.0 63.0 230.0 71.0 237.0 80.0 245.0105.0 248.0 110.0 289.0 121.0 296.0 148.0 300.0 204.0 300.0 214.0 364.0216.0 365.0 234.0 371.0 242.0 457.0 262.0 461.0 266.0 517.0 286.0 557.0297.0 636.0 349.0 736.0 358.0 820.0 673.0 900.0Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal (39 animals per treatment group).Data is rank-ordered.

Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal (39 animals per treatment group). Data isrank-ordered. TABLE 3 Effects of Different Doses of C105 on InhibitoryAvoidance Saline 0.4 mg/kg 0.5 mg/kg 0.75 mg/kg 1.0 mg/kg 2.0 mg/kg 17.045.0 16.0 9.0 101.0 30.0 55.0 62.0 38.0 15.0 115.0 59.0 60.0 80.0 137.016.0 121.0 59.0 77.0 87.0 203.0 21.0 202.0 127.0 103.0 170.0 267.0 150.0265.0 137.0 107.0 231.0 332.0 157.0 343.0 230.0 116.0 236.0 556.0 229.0729.0 231.0 129.0 250.0 698.0 237.0 813.0 253.0 237.0 813.0 253.0 288.0824.0 366.0 240.0 265.0 741.0 288.0 824.0 366.0 280.0 629.0 900.0 650.0900.0 384.0Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal (10 animals per treatment group). Data isrank-ordered.

TABLE 4 Effects of Low Doses of C105 on Inhibitory Avoidance Saline 0.1mg/kg 0.25 mg/kg 0.5 mg/kg 33.0 37.0 24.0 127.0 38.0 37.0 28.0 137.055.0 39.0 29.0 144.0 62.0 39.0 71.0 164.0 80.0 55.0 71.0 167.0 100.055.0 100.0 182.0 216.0 110.0 113.0 219.0 235.0 113.0 117.0 265.0 370.0124.0 120.0 362.0 518.0 366.0 205.0 886.0Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal (10 animals per treatment group).Data is rank-ordered.

TABLE 5 Summary of the Effects of C105 (0.5 mg/kg) or Saline onInhibitory Avoidance Saline C105 21.0 21.0 21.0 33.0 24.0 40.0 26.0 41.027.0 43.0 27.0 63.0 33.0 65.0 38.0 65.0 39.0 66.0 39.0 79.0 55.0 126.059.0 127.0 59.0 137.0 62.0 154.0 75.0 164.0 79.0 167.0 80.0 181.0 96.0182.0 100.0 188.0 109.0 219.0 109.0 225.0 113.0 225.0 113.0 261.0 121.0265.0 121.0 357.0 168.0 362.0 179.0 418.0 179.0 444.0 193.0 521.0 216.0540.0 235.0 556.0 235.0 595.0 248.0 660.0 370.0 880.0 431.0 886.0 431.0900.0 518.0 900.0 17.0 16.0 23.0 37.0 27.0 38.0 33.0 52.0 36.0 137.040.0 170.0 41.0 184.0 46.0 203.0 47.0 209.0 48.0 231.0 55.0 267.0 55.0273.0 56.0 293.0 60.0 332.0 74.0 426.0 77.0 556.0 82.0 582.0 92.0 698.0103.0 741.0 105.0 900.0 107.0 108.0 114.0 116.0 120.0 120.0 129.0 154.0176.0 204.0 218.0 225.0 240.0 281.0 334.0 518.0 680.0 900.0 900.0 900.0Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal.This table reflects data gathered from all experiments conducted usingC105.The number of animals in the saline (n = 77) and drug conditions (n =57) differ because in several experiments, extra control animals wererun.Data is rank-ordered.

Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal. This table reflects data gathered from allexperiments conducted using C105. The numbers of animals in the saline(n=77) and drug conditions (n=57) differ because in several experiments,extra control animals were run. Data is rank-ordered. TABLE 6 Effects ofPost-Training Administration of C105 on Inhibitory Avoidance Saline C10517.0 38.0 25.0 65.0 26.0 77.0 34.0 112.0 36.0 123.0 37.0 133.0 41.0170.0 64.0 185.0 64.0 194.0 120.0 223.0 137.0 276.0 175.0 338.0 271.0603.0 349.0 824.0Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal (14 animals per treatment group).Data is rank-ordered.

TABLE 7 Effects of C105 on Inhibitory Avoidance in Control and FornixLesion Rats Control Fornix Control Fornix Control Fornix Control FornixControl Fornix Saline Saline 0.5 mg/kg 0.5 mg/kg 1.0 mg/kg 1.0 mg/kg 2.0mg/kg 2.0 mg/kg 4.0 mg/kg 4.0 mg/kg 50.0 * 28.0 4.0 26.0 ** 21.0 4.021.0 2.0 72.0 ** 28.0 7.0 26.0 4.0 25.0 17.0 36.0 8.0 92.0 2.0 93.0 13.048.0 7.0 41.0 18.0 64.0 13.0 123.0 19.0 162.0 21.0 56.0 19.0 84.0 26.064.0 21.0 126.0 22.0 214.0 21.0 106.0 19.0 86.0 28.0 83.0 25.0 164.023.0 240.0 32.0 195.0 166.0 92.0 30.0 83.0 28.0 180.0 35.0 252.0 55.0197.0 221.0 106.0 40.0 86.0 42.0 217.0 40.0 271.0 65.0 213.0 246.0 160.070.0 98.0 96.0 222.0 72.0 284.0 72.0 238.0 274.0 192.0 84.0 193.0 140.0228.0 141.0 577.0 209.0 317.0 314.0 581.0 153.0 208.0 159.0Data are expressed as latency to enter the dark side of the apparatus inseconds for each animal (10 animals per treatment group). Data isrank-ordered.* animal died during surgery - no data available** data from these subjects excluded from analysis as they wereoutliers: more than two SD's away from the mean

TABLE 8 Effects of C105 on Spontaneous Object Recognition: Control Data,Discrimination Index D1 Saline C105 −1.00 * −1.00 1.00 0.87 5.00 1.595.00 2.00 6.00 2.00 6.47 3.00 7.00 3.00 8.00 3.82 8.00 3.92 9.00 4.009.00 4.00 9.76 4.84 12.00 4.97 12.06 5.00 12.31 6.00 13.00 7.00 13.007.00 13.29 7.60 14.03 8.00 16.00 9.00 16.00 10.00 18.59 11.00 20.0018.00 20.00 23.00 20.00 23.00 22.00 32.00 26.00* data for one subject in the C105 excluded as it was an outlier - morethan two SD's away from the mean.Data is rank-ordered.

TABLE 9 Effects of C105 on Spontaneous Object Recognition: Fornix Data,Discrimination Index D1 Fornix + Saline Fornix + C105 * −4.79 ** −0.12** 0.00 −2.60   1.92 −0.60   3.00 −0.30   3.26 0.00 5.00 0.00 6.00 1.006.00 1.00 6.00 2.90 8.00 3.00 9.00 3.00 12.30 4.00 14.80 7.00 16.4610.00  18.00 17.00  19.29* animal died during surgery: no data collected** data for these two animals not videotapedData is rank-ordered.

TABLE 10 Effects of C105 on Spontaneous Object Recognition: ControlData, Discrimination Index D2 Saline C105 −5.88 * −3.03 4.00 6.48 10.208.69 24.32 8.77 25.00 10.00 25.30 14.29 27.14 17.95 30.36 20.67 31.3322.09 33.52 22.48 36.36 22.58 37.14 23.08 39.37 23.18 41.18 25.00 42.1127.27 47.06 30.77 47.83 31.43 48.15 33.33 52.94 35.58 55.56 45.45 55.5650.00 55.61 51.11 57.50 52.84 63.29 53.49 76.47 56.25 83.33 66.67 100.00* data excluded because it was more than 2 SD's away from the meanData is rank-ordered.

TABLE 11 Effects of C105 on Spontaneous Object Recognition: Fornix Data,Discrimination Index D2 Fornix + Saline Fornix + C105 * −26.45 ** −0.75** 0.00 −14.29 9.50  −8.78 15.55  −5.23 17.64    0.00 22.22    0.0027.09    2.84 29.41    7.69 30.00    9.09 31.25   10.59 36.00   20.0037.50   30.28 40.91   33.33 42.86   48.57 55.45   50.00 62.34* animal died during surgery: no data collected** data for these two animals not videotapedData is rank-ordered.

TABLE 12 Effects of C105 on Tail-Flick Analgesia Saline 1.0 mg/kg 2.0mg/kg 4.0 mg/kg 8.0 mg/kg 1.55 1.13 2.46 2.22 * 2.19 2.28 2.68 3.13 3.132.37 3.26 2.79 5.43 4.67 2.71 3.30 3.05 6.26 4.72 3.44 4.59 3.56 6.425.22 3.58 4.60 3.89 6.66 6.54 3.64 5.09 3.96 16.44 7.39 5.34 6.01 4.4520.00 14.43* no data for this subject was collectedData is rank-ordered.

Example 9 Comparison of D-Amphetamine, L-Amphetamine andL-Methamphetamine

Materials and Methods

Animals

Male, Long-Evans rats (3-5 months of age) obtained from Charles RiverLaboratories weighing between 250 and 350 grams at the time of arrivalserved as subjects in these experiments. The rats were housed two to acage in plastic cages with corncob bedding. The rats were maintained ona 12/12 light dark cycle with ad libitum access to food and water.

Drugs

L-methamphetamine (SN522), l-amphetamine (C105) and d-amphetamine weredissolved in saline and administered to the rats via intraperitoneal(i.p.) injections, in a volume of 1 ml/kg body weight.

Experiment 1: Passive Avoidance Test

The Passive Avoidance apparatus (Coulbourn Instruments) consisted of alight chamber and a dark chamber, which were joined by means of asliding guillotine door. The floor of the dark compartment consisted of2.4 mm diameter steel rods, through which a foot-shock could beadministered to the animal by a constant current 18-pole shockscrambler. The test apparatus was enclosed in a ventilated,sound-attenuating cabinet, and was controlled by Graphic State™ Software(Version 1.013) and a Hewlett Packard Pavilion Computer.

Training involved placing the rat inside the light chamber with its headfacing away from the door. Ten seconds later, the sliding door wasopened, and the latency to enter the dark chamber was recorded (100second maximum). When the rat entered the dark chamber, it received acontinuous foot-shock (0.4 mA) through the metal grid floor until itreturned in the light chamber for a period of 100 consecutive seconds oruntil a maximum of 5 foot-shocks had been received.

Retention testing was conducted 24 hours later. The rat was placed intothe light chamber with its head facing away from the door. Ten secondslater, the door was opened, alloweing the rat access to the darkchamber. No foot-shock was administered during retention testing.Latency to enter the dark chamber was recorded (900 seconds maximum) andused as a measure of memory.

In this experiment, rats were injected (ip) immediately after trainingwith saline (control/vehicle), SN522 (0.25 and 0.5 mg/kg), C105 (0.5 and1.0 mg/kg) or d-amphetamine (1.0 and 2.0 mg/kg). Retention was tested 24hours after training.

The results from this experiment are illustrated in FIG. 20 anddemonstrate that the different doses of the three drugs differ in termsof their potency. FIG. 20 depicts a comparison of d-amphetamine, C105and SN522 administered immediately after training in inhibitoryavoidance. Data show the mean (±SEM) step-through latency (seconds) on atest 24 hours following training. Separate groups of animals (n=10 foreach treatment group) were injected (ip) with vehicle (0.9% saline),d-amphetamine (1.0, or 2.0 mg/kg), C105 (0.5 or 1.0 mg.kg) or SN522(0.25 or 0.5 mg/kg) immediately after training. Data were analyzed usingCox regression within a Kaplan-Meier survival analysis (p<0.05).

A Kaplan Meier Survival Analysis demonstrated that doses of 0.5 mg/kg ofC105, 2.0 mg/kg d-amphetamine and 0.5 mg/kg SN522 significantly improvedperformance on this task (p values=0.007, 0.0004, and 0.03respectively). Thus, l-methamphetamine and l-amphetamine significantlyimprove memory consolidation.

Example 10 L-Methamphetamine and Memory

Materials and Methods

Animals

Male, Long-Evans rats (3-5 months of age) obtained from Charles RiverLaboratories weighing between 250 and 350 grams at the time of arrivalserved as subjects in these experiments. The rats were housed two to acage in plastic cages with corncob bedding. The rats were maintained ona 12/12 light dark cycle with ad libitum access to food and water.

Drugs

L-methamphetamine (SN522) was dissolved in saline and administered tothe rats via intraperitoneal (i.p.) injections, in a volume of 1 ml/kgbody weight.

Results and Discussion

Experiment 1: Passive Avoidance

The Passive Avoidance apparatus (Coulbourn Instruments) consisted of alight chamber and a dark chamber, which were joined by means of asliding guillotine door. The floor of the dark compartment consisted of2.4 mm diameter steel rods, through which a foot-shock could beadministered to the animal by a constant current 18-pole shockscrambler. The test apparatus was enclosed in a ventilated,sound-attenuating cabinet, and was controlled by Graphic State™ Software(Version 1.013) and a Hewlett Packard Pavilion Computer.

Training involved placing the rat inside the light chamber with its headfacing away from the door. Ten seconds later, the sliding door wasopened, and the latency to enter the dark chamber was recorded (100second maximum). When the rat entered the dark chamber, it received acontinuous foot-shock (0.4 mA) though the metal grid floor until itreturned to the light chamber. This sequence of events was continueduntil the rat remained in the light chamber for a period of 100consecutive seconds or untilo a maximum of 5 foot-shocks had beenreceived.

Retention testing was conducted 24 hours later. The rat was placed intothe light chamber with its head facing away from the door. Ten secondslater, the door was opened, allowing the rat access to the dark chamber.No foot-shock was administered during retention testing. Latency toenter the dark chamber was recorded (900 seconds maximum) and used as ameasure of memory.

In this experiment, the effects of SN522 on consolidation of the passiveavoidance task were investigated. Rats were injected with saline(contol, no or zero drug) or six different doses (0, 0.10, 0.25, 5.0,0.75 or 1.0 mg/kg, i.p.) of SN522 immediately after the trainingsession. Retention for the task was tested 24 hours later.

The results from this experiment are illustrated in FIG. 21. FIG. 21depicts the effects of SN522 administered immediately after training ininhibitory avoidance. Data show the mean (±SEM) step-through latency(seconds) on a test 24 hours following training. Separate groups ofanimals (number of animals in each treatment group indicated insidebars) were injected with vehicle (0.9% saline) or one of five doses ofSN522 (0.1, 0.25, 0.5, 0.75, or 1.0 mg/kg). Data were analyzed usine Coxregression within a Kapaln-Meier survival analysis (p<0.05).

The step-through latency in response to SN522 is an inverted U-shapeddose response curve. A Kaplan Meier survival analysis with coxregression confirmed significant improvement in memory performancerelative to the saline group at doses of 0.25, 0.5, and 0.75 mg/kg(p<0.05).

Experiment 2: Water Maze

Water Maze testing (Morris, R., J. Neurosci Methods 11:47-60 (1984)) wasconducted in a galvanized steel pool, painted white, measuring 180 cm indiameter and 60 cm in height. The pool was equipped with a removablecircular platform (10 cm in diameter) made of clear Plexiglas. The poolwas filled with water (26° C.) to a level of 1 cm above the surface ofthe platform. Nontoxic white paint was added to the water to obscure theplatform's appearance. The pool was divided conceptually into fourquadrants and the platform was located in the NW quadrant 30 cm from thepool wall. Extramaze cues were provided by large geometric shapesadhered to curtains that surrounded two sides of the pool, and byshelving units, a sink, and posters on the visible walls.

The training procedure involved placing the rat into the water, with therat's head facing the wall of the pool, at one of four differentstarting points. The rat was allowed 60 seconds to locate the hiddenplatform. If the rat did not find the platform within 60 seconds, it wasgently guided to the platform. After 15 seconds spent on the platform atthe end of each trial, the rat was removed from the pool and injectedwith saline or SN522 (0.25 and 0.5 mg/kg, i.p.). The rat was dried, andreturned to its home cage. One trail was conducted each day for 10 days.The latency to reach the platform (escape latencey) was recorded on eachdays training trial.

An ANOVA show a significant enhancement in acquisition rate in animalsadministered 0.25 mg/kg SN522 relative to controls (See FIG. 22;F_(1, 17)=10.245, p<0.005).

FIG. 22 depicts the effect of SN522 on acquisition of the water mazetask. Data are the mean (±SEM) latency to locate a hidden platform bythree separate groups of rats (n=10 for each treatment group). Animalswere given a single learning trial each day. Immediately following thelearning trial, vehicle (saline) or SN522 (0.25 or 0.5 mg/kg) wereadministered IP. The data show that while all groups learned to find theplatform during the 10 training days indicated by the decrease in escapelatency, animals that were treated with 0.25 mg/kg SN522 after eachtrial learned to find the platform more quickly than rats in the salinetreated group.

The comparison between the control (saline) group and the groupadministered the higher dose of SN522 did not reveal any statisticaldifferences (p>0.05). These data confirm that SN522 has potent effectson mnemonic processing.

FIG. 23 depicts the effect of SN522 on activity levels measured by anautomated motion detector. Data are the mean activity (±SEM) of fourseparate groups of rats (n=7 or 8 per group) treated with SN522 (0.25,0.5, 2.5, and 5.0 mg/kg, ip) as measured by an activity monitor system,tracking beam breaks around an open field. Data are shown as a percentchange from a control group treated with vehicle (0.9% saline). The datashow that doses of l-methamphetamine (SN522) have profound effects onmemory processes produce no or modest changes in motor behavior (0.25and 0.5 mg/kg). Doses of SN522 ten times over the therapeutic dosesyielded only mild increases in activity. Thus, l-methamphetamine has noor minimal side effects.

Experiment 3: Locomotor Activity

Activity monitoring was conducted in a Plexiglas open-field boxmeasuring 30 by 30 cm. Activity levels were measured via a grid ofinfrared light beams that traversed the cage from left to right and backto front. The location of the animal within the cage was detected bybreaks in the infrared light beams. Light beams status information wascollected and rapidly analyzed by a computerized activity monitoringsystem (VersaMax System, Accuscan Instruments.)

In order to determine whether SN522 had any adverse effects on locomotoror exploratory activity, rats were injected with saline or 0.25, 0.5,2.5 and 5.0 mg/kg of SN522 and immediately afterwards placed into theactivity monitoring chambers for a period of three hours. Data wascollected on-line using Versa Max (Version 1.83) computer software and aHewlett Packard Pavilion computer. Analyzed behaviors included;horizontal activity, total distance moved, movement time, number ofmovements, number of rears, number of stereotyped movements, and timespent resting.

FIG. 24 depicts the effect of d-amphetamine on activity levels measuredby an automated motion detector. Data are the mean activity (±SEM) offour separate groups of rats treated with SN522 Mean activity (±SEM) offour separate groups of rats (n=7 or 8 per group) treated withd-amphetamine sulfate (0.25, 0.5, 2.5, and 5.0 mg/kg, ip). Data areshown as a percent change from a control group treated with vehicle(0.9% saline). The data show that even very low doses of d-amphetaminehave effects on activity. These effects are significant even at the verylowest dose tested (0.25 mg/kg), with profound increases in activity atthe higher doses all p's,0.05.

As can be seen in FIG. 24 (data are shown as a percent increase relativeto the saline control), low doses SN522 resulted in no increase inactivity at doses that were efficacious in the memory assays (0.25mg/kg, p>0.05), and produced only modest increases in activity at aslightly higher dose (0.5 mg/kg; F_(8, 112)=2.303, p=0.028). Relativelyhigh doses of SN522 (2.5 and 5.0 mg/kg) resulted in small, butsignificant increases in activity relative to the saline control (0.25mg/kg; F_(8, 112)=10.936, p<0.001; 5.0 mg/kg; F_(8, 112)=8.749,p<0.001). However, when compared with activity produced by similar dosesof d-amphetamine, the increases in activity levels after administrationof SN522 are minimal indicating minimal side effects from SN522.

Experiment 4: Tailflick Test of Analgesia

The tail-flick response was assessed using a radiant heat tail flickmonitor (Accuscan Instruments model TFS) equipped with a radiant heatelement and two light beam sensors to detect tail movement.

In order to determine whether SN522 has any analgesic properties, rats(n=10 per treatment group) were injected with saline or SN522 (0.25,0.5, 2.5 and 5.0 mg/kg, i.p.) and tested at four time points:immediately prior to injection, and again 15, 30, and 60 minutesfollowing drug administration for a tail flick response (D'Amour, F. E.,et al., J. Pharmacol. Exp. Ther. 72:174-179 (1941)). To test thetail-flick, the animal was placed on top of the Tail-Flick monitor andgently held in place with a cotton towel. The tail of the animal wasplaced in a shallow groove lying between the two sensors and over thetop of the radiant heat wire. The heat element was activated, and thelatency for the animal to flick its tail out of the groove and away fromthe heat source was automatically recorded via activation of thesensors. The intensity of the heat source was adjusted so that theanimal flicked its tail within 3-4 seconds. A 10 second cutoff wasimposed to avoid tissue damage. The animal was returned to its home cageimmediately following testing.

The results of an ANOVA over the five drug treatments and four testintervals did not reveal any differences in tail flick latency. Thus,SN522 does not alter pain sensitivity in this test.

Example 11 Study of (R)-(−)-Amphetamine in Humans

Sixteen (n=16) healthy adult male/female subjects, ages 20-72, took partin the study. Subjects were selected from a volunteer database.Study-related procedures were carried out after informed consent hadbeen given.

FIG. 18 shows a pharmacokinetic measure, in the form of serum levels,for (R)-(−)-amphetamine up to 6 hours after administration. In theascending dose portion of the dose curve, the Brief Visuospatial MemoryTest (BVMT) and Rey Auditory and Verbal learning Test (RAVLT) tests wereperformed and observed to be stastistically significantly higher whencompared to controls, having a p<0.01. Higher BVMT and RAVLT scoresindicate an improvement in memory, in particular memory consolidation.On the other hand, patients were assessed using the ProvidenceRecognition Memory Test (Pictoral) after 3 hours, e.g., after theascending arm of the dose curve, and the PRMT scores (both for words andpictures) were both not observed to be statistically significant fromcontrols. These experiments demonstrate that (R)-(−)-amphetamine canenhance memory in patients, and is more effective during the ascendingportion of the plasma curve.

FIG. 19 shows a dose response curve for acute dosing with(R)-(−)-amphetamine. Statistically signifcant differences, e.g., asillustrated by the p values, were observed between pacebo and dosages ofabout 30 mg and about 45 mg per day. In particular, at 30 min: p=0.004for placebo vs about 30 mg, and p=0.03 for placebo vs. about 45 mg. At24 hour, p=0.002 for placebo vs about 30 mg, and p=0.05 for placebo vsabout 45 mg.

Example 12 Improvement in Memory in Humans with l-Amphetamine

Two (2) Phase 1 randomized, double-blind, placebo-controlled clinicalstudies of l-amphetamine (C105) were conducted in normal healthy adultmale and female subjects. The first trial was conducted in eight (8)Caucasian subjects (3 male and 5 female) with a mean age of 35.1 years(range 21-49 years), and the second trial was conducted in eight (8)Caucasian subjects (1 male and 7 female) with a mean age of 65.4 years(range 60-72 years).

The studies were intended to identify the maximum tolerated dose (MTD)and dose-limiting side effects of C105, to assess the effects of C105 onquantitative memory scores, to assess the perceived central nervoussystem (CNS) effects following C105 administration, to assess theeffects of C105 on the cardiovascular system, to explore therelationship between dose, tolerability, safety and pharmacologicaleffects of C105, and to define the pharmacokinetics (PK) of C105.

There were five (5) treatment periods in each Phase 1 trial. Eachtreatment period was one (1) week in duration and consisted of two (2)consecutive days of treatment (“treatment period”) with C105 (5 mg, 15mg, 30 mg, 45 mg) or placebo, followed by five (5) consecutive dayswithout C105 or placebo (“washout period”). The design is a ascendingdose safety design with a placebo dose randomly inserted iinto thesequence. Each subject was randomly administered a single dose of one ofthe C105 doses (5 mg, 15 mg, 30 mg, 45 mg) or a randomly assigned doseof placebo during each treatment period on the two consecutive treatmentdays. Each subsequent treatment group would included whatever dose ofC105 (or placebo) had not previously been administered, until thepatient had received each of the four C105 doses (5 mg, 15 mg, 30 mg, 45mg) or single placebo treatment to conclude the five week treatmentperiod. Safety data were reviewed after each dose prior to advancementto the next dose level.

The Rey Auditory Visual Learning Test (RAVLT, Rey, A. (1941). L'examenpsychologique dans les cas d'encéphalopathie traumatique. Archives dePsychologie, 28, 21, Lezak, M. D. (1995). Neuropsychological Assessment(3rd ed.). New York: Oxford University Press) was conducted during eachof the two consecutive days when the patent received C105 or placebo.RAVLT was not conducted during the washout period.

The RAVLT assessment for word recall was made at two (2) different timesfollowing C105 or placebo treatment during each of the five treatmentperiods. The first RAVLT assessment was made on the first day oftreatment in each treatment period and consisted of two parts. Fifteen(15) nouns were read aloud to the patient by an Examiner, followed by aninterference or distraction trial, which is then followed by afree-recall test of the 15 nouns. After a additional 30-minute delayperiod, the subject was again required to recall the first set of 15nouns and also complete a 50-word recognition test. The second RAVLTassessment was made on the second day of treatment in each treatmentperiod and consisted of a repeat of the Recall test and the 50-wordRecognition test given on the previous day. The second RAVLT assessmentevaluated word recall 24 hours (±2 hours) after the first RAVLTassessment and did not consist of another exposure to nouns by anExaminer, but rather a recall of the nouns given to the subject 24 hoursearlier.

Safety and tolerability assessments were changes in vital signs, ECGs,Holter monitoring, laboratory tests, physical examination and adverseevents. Serial blood and urine samples were collected up to 24 hoursafter dosing for subsequent determination of C105 plasma concentrationsand calculation of pharmacokinetic parameters.

C105 was well tolerated when administered in single oral doses rangingfrom 5 to 45 mg. Reported adverse events were minor. The most frequentlyreported adverse events were dizziness, headache, insomnia, sinustachycardia, supraventricular tachycardia and aptyalism. Reportedadverse events were generally mild in severity and resolved withoutrequiring treatment. There were no reported serious adverse events andno subject was discontinued from the study due to an adverse event.There were no clinically meaningful findings with respect to C105administration on physical examinations, laboratory tests, vital signs,12-lead ECGs or Holter recordings.

For each patient, RAVLT data showed that all dose groups have meanvalues higher than the placebo at 30 minutes. The two highest doses (30mg and 45 mg) exhibited the greatest improvement (highest values)compared to placebo testing. The benefit observed at 30 minutes wasmaintained at 24 hours, with the recalled number of words slightly lowerat 24 hours for each dose compared to the corresponding results at 30minutes. The recall scores were approximately 10 words followingadministration of the 45 mg dose, compared to approximately 7-8 wordsrecalled when the placebo dose had been administered.

FIG. 25 shows a pooled statistical analysis of the 30-minute and 24-hourRAVLT memory scores for all subjects. The scores showed an overallstatistically significant (p<0.05) improvement in RAVLT score withrespect to C105 dose at both 30 minutes and 24 hours post-treatment. Inaddition, improvements in RAVLT scores observed with the 30 mg and 45 mgdoses of C105 were statistically significant (p<0.05), based on theWilcoxon signed rank test, when compared to placebo at both 30 minutesand 24 hours post-dose. The difference is also significant (p=0.0559) atthe 5 mg dose for the 24-hour recall scores. A comparison of eachindividual subject's placebo score to their best score on any dose ofC105 showed that RAVLT memory performance for all subject (except forone subject who had a perfect RAVLT score under both conditions)improved following C105 treatment (see FIG. 26).

These data demonstrate that l-amphetamine (C105) enhance memory, inparticular memory consolidation.

Equivalents

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention as defined by the appended claims.

All patents, publications, and other references cited above are herebyincorporated by reference in their entirety.

1. A method of improving memory consolidation in a human, comprising thestep of administering at least one member selected from the groupconsisting of l-amphetamine and l-methamphetamine to a human having animpairment in memory consolidation.
 2. The method of claim 1, whereinl-amphetamine is administered, and wherein the l-amphetamine isadministered as a component of a composition that includes at leastabout 80 mole percent l-amphetamine relative to a total amphetaminecontent of the composition.
 3. The method of claim 1, whereinl-methamphetamine is administered, and wherein the l-methamphetamine isadministered as a component of a composition that includes at leastabout 80 mole percent l-methamphetamine relative to a totalmethamphetamine content of the composition.
 4. The method of claim 1,wherein the impairment in memory consolidation in the human isdetermined by a Rey Auditory Verbal Learning Test.
 5. The method ofclaim 1, wherein l-amphetamine and l-methamphetamine is administered ina single dose.
 6. The method of claim 5, wherein the single dose is adose of at least about a 0.01 mg dose.
 7. The method of claim 1, whereinthe l-amphetamine and l-methamphetamine is administered in multipledoses.
 8. The method of claim 7, wherein each dose of the multiple dosesis administered at a dose of at least about a 0.01 mg dose.
 9. A methodof improving memory consolidation in a human, comprising the step ofadministering at least one member selected from the group consisting ofl-amphetamine and l-methamphetamine to a human having an impairment inmemory consolidation, wherein the l-amphetamine is administered as acomponent of a composition that includes at least about 80 mole percentl-amphetamine relative to a total amphetamine content in the compositionand the l-methamphetamine is administered as a component of acomposition that includes at least about 80 mole percentl-methamphetamine relative to a total methamphetamine content in thecomposition.
 10. The method of claim 9, wherein the impairment in memoryconsolidation in the human is determined by a Rey Auditory VerbalLearning Test.
 11. The method of claim 9, wherein the l-amphetamine andl-methamphetamine is administered as a single dose.
 12. The method ofclaim 11, wherein the single dose is a dose of at least about a 0.01 mgdose.
 13. The method of claim 9, wherein the l-amphetamine andl-methamphetamine is administered in multiple doses.
 14. The method ofclaim 13, wherein each dose of the multiple doses is administered at adose of at least about a 0.01 mg dose.
 15. A method of improving memoryconsolidation in a human, comprising the step of administering at leastone member selected from the group consisting of l-amphetamine andl-methamphetamine to a human having an impairment in memoryconsolidation, wherein the l-amphetamine is administered as a componentof a composition that includes at least about 90 mole percentl-amphetamine relative to a total amphetamine content in the compositionand the l-methamphetamine is administered as a component of acomposition that includes at least about 90 mole percentl-methamphetamine relative to a total methamphetamine content in thecomposition.
 16. A method of improving memory consolidation in a human,comprising the steps of: a) assessing the degree of an impairment inmemory consolidation in a human; b) administering at least one memberselected from the group consisting of l-amphetamine andl-methamphetamine to the human; and c) determining the improvement inmemory consolidation after administering the l-amphetamine andl-methamphetamine to the human.
 17. The method of claim 16, furtherincluding the step of comparing the impairment in memory consolidationin the human before administering the l-amphetamine andl-methamphetamine to the improvement in memory consolidation in thehuman after administering the l-amphetamine and l-methamphetamine. 18.The method of claim 16, wherein memory consolidation is assessed anddetermined by a Rey Auditory Verbal Learning Test.
 19. The method ofclaim 16, wherein the l-amphetamine and l-methamphetamine isadministered in a dose of at least about a 0.01 mg dose.
 20. The methodof claim 16, wherein l-amphetamine is administered, and wherein thel-amphetamine is administered as a component of a composition thatincludes at least about 80 mole percent l-amphetamine relative to atotal amphetamine content of the composition.
 21. The method of claim16, wherein l-methamphetamine is administered, and wherein thel-methamphetamine is administered as a component of a composition thatincludes at least about 80 mole percent l-methamphetamine relative to atotal methamphetamine content of the composition.
 22. The method ofclaim 16, wherein the l-amphetamine and l-methamphetamine isadministered in a single dose.
 23. The method of claim 16, wherein thel-amphetamine and l-methamphetamine is administered in multiple doses.